U.S. patent number 3,766,910 [Application Number 05/079,372] was granted by the patent office on 1973-10-23 for disposable delicate tissue retractor.
Invention is credited to Peter A. Lake.
United States Patent |
3,766,910 |
Lake |
October 23, 1973 |
DISPOSABLE DELICATE TISSUE RETRACTOR
Abstract
A disposable self-retaining brain and delicate tissue retractor
with interchangeable disposable blades. The retractor and blades
are designed to be molded from a lightweight material such as a
plastic. The blades may be made of various shapes and sizes and, in
most instances, are designed to be coated with a strip of gauze
like material to protect and prevent injury to the brain or other
soft tissue.
Inventors: |
Lake; Peter A. (Palm Springs,
CA) |
Family
ID: |
22150116 |
Appl.
No.: |
05/079,372 |
Filed: |
October 9, 1970 |
Current U.S.
Class: |
600/213; 600/217;
600/226; 600/219; 606/198 |
Current CPC
Class: |
A61B
17/0206 (20130101) |
Current International
Class: |
A61B
17/02 (20060101); A61b 017/02 () |
Field of
Search: |
;24/2TT,248L,255SL,255TZ
;128/17,18,19,20,242,243,244,341,345 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
339,072 |
|
Apr 1936 |
|
IT |
|
11,426 |
|
1901 |
|
GB |
|
559,239 |
|
Jul 1957 |
|
BE |
|
Primary Examiner: Howell; Kyle L.
Claims
I claim:
1. A soft tissue retractor comprised of blades, a body member and a
locking means,
said body member having first and second end regions and being
curved so as to enclose an area, with said first and second end
regions adjacently disposed in overlapping relationship with
respect to each other, said body member including integral
therewith two adjacent generally coplanar elongated members
extending therefrom generally in the plane of said body member, and
extending from one side of said body member;
said elongated members each supporting one of said blades near the
outer end of said elongated member;
said blades being disposed in a plane substantially normal to the
longitudinal axis of said elongated members and adapted to retract
soft tissue;
said locking means including means to retain said first and second
end regions in any of a plurality of relative dispositions whereby
said blades may be retained at any of a selection of
separations.
2. The retractor of claim 1 wherein said body member further
includes two finger grips extending from whereby finger pressure
may be applied to said finger grips to encourage said blades to
different separations.
3. The retractor of claim 1 wherein said locking means includes a
separate member adapted to engage with said end regions.
4. The retractor of claim 1 wherein said blades are detachable from
said elongated members and said blades and said elongated members
contain mating surfaces, said mating surfaces being adapted to
allow said blades and said elongated members to be pushed together
and retained, one to the other.
5. The retractor of claim 1 wherein one blade includes at least one
hook-like protrusion to locate with respect to bone structure.
6. The retractor of claim 1 further comprised of gauze-like pads on
said blades, said gauze-like pads having an adhesive backing to
adhere to said blades, wherein said gauze-like pads substantially
fully surround the portion of each of said blades which is adapted
to retract soft tissue, said pads being constructed in the form of
an envelope and being open only at one edge to facilitate the
placement of said pads on the blades and to allow the protrusion of
the portion of said blades that connects with said elongated
members.
7. The retractor of claim 1 wherein said retractor is constructed
of plastic.
8. The retractor of claim 1 wherein said body member has
cooperatively disposed toothed regions adjacent its said ends and
means for elastically encouraging said toothed regions to mate to
retain said blades at any of a selection of separations.
9. A soft tissue retractor comprised of two blades, a body member
and a locking means,
said body member being a ring member having two adjacent generally
coplanar elongated members extending therefrom generally in the
plane of said body member, and extending from one side of said body
member;
said elongated members each supporting one of said blades near the
outer end of said elongated member;
said blades being disposed in a plane substantially normal to the
longitudinal axis of said elongated members and adapted to retract
soft tissue;
said ring member having a tongue member forming a portion of the
arc of said ring member and extending between two mating members of
said ring member;
said mating members also forming a portion of the arc of said ring
member;
said tongue member and said mating members each having a plurality
of holes therein;
said holes being disposed so as to form at least one continuous
hole through said tongue member and said mating members at a
plurality of separations of said blades;
said locking means including at least one pin member, said pin
member being adapted for insertion into a continuous hole through
said tongue member and said mating members to lock said blades at
any of said plurality of separations.
10. The retractor of claim 9 wherein said body member elastically
encourages said blades to greater separations, said body member
further including two fingers grips extending therefrom whereby
finger pressure may be applied to said finger grips to encourage
said blades to smaller separations.
11. A soft tissue retractor comprised of two blades and a body
member,
said body member having first and second ends and being curved so
as to enclose an area with its ends overlapping, said body member
having two adjacent generally coplanar elongated members extending
therefrom generally in the plane of said body member, and extending
from one side of said body member;
said elongated members each supporting one of said blades near the
outer end of said elongated members;
said blades being disposed in a plane substantially normal to the
longitudinal axes of said elongated members and adapted to retract
soft tissue;
said body member having cooperatively disposed toothed regions
adjacent its said ends, and means for elastically encouraging said
toothed regions to mate to retain said blades at any of a selection
of separations.
12. The soft tissue retractor of claim 11 wherein said teeth are
inclined to provide means to allow movement of said retractor
blades to greater separations and to prevent substantial movement
of said retractor blades to lesser separations without elastically
and separately forcing said toothed regions out of engagement.
13. The retractor of claim 11 wherein said body member further
includes two extending finger grips whereby finger pressure may be
applied to said finger grips to encourage said blades to increased
separations.
14. The retractor of claim 11 wherein said body member further
includes two extending release grips whereby finger pressure may be
applied to said release grips to encourage said toothed regions
into separation.
15. The retractor of claim 11 wherein the portion of said body
member between said elongated arms comprises means elastically
encouraging said retractor blades to lesser separations.
16. The retractor of claim 11 wherein said blades are detachable
from said elongated members and said blades and said elongated
members contain mating surfaces, said mating surfaces being adapted
to allow said blades and said elongated members to be pushed
together and retained, one to the other.
17. The retractor of claim 11 wherein one blade include at least
one hook-like protrusion to locate with respect to bone
structure.
18. The retractor of claim 11 further comprised of gauze-like pads
on said blades, said gauze-like pads having an adhesive backing to
adhere to said blades, wherein said gauze-like pads substantially
fully surround the portion of each of said blades which is adapted
to retract soft tissue, said pads being constructed in the form of
an envelope and being open only at one end to facilitate the
placement of said pads on the blades and to allow the protrusion of
the portion of said blades that connects with said elongated
members.
19. The retractor of claim 11 wherein said retractor is constructed
of plastic.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of surgical devices and more
particularly to soft tissue retraction surgical devices.
2. Prior Art
An important part of all surgical procedures is exposure of an
adequate operative field. To do this, soft tissue must be retracted
for prolonged periods. By way of example, in brain surgery, it is
often necessary to incise through brain tissue and retract it aside
to reach for tumors or blood clots deep within the brain substance.
Also, many operations are designed to elevate the brain from the
floor of the skull by retraction in order to reach the blood
vessels and structures beneath the brain.
Existing brain retractors in current use are of two types. There
are bent metal retractors, somewhat similar in shape to the
familiar tongue depressor, in general being bent to achieve more
complicated shapes. Such instruments are held by hand and,
therefore, require the surgeon to perform all other tasks with the
remaining hand. These instruments are further limited by the fact
that they retract only one lip or side of an incision at a time
and, because they are hand-held, the pressure applied to the
tissue, such as the brain, is variable with the delicacy and length
of the operating procedure. In addition, they are relatively
expensive, ranging in price from $3.00 to $25.00 for each
retractor.
The second type of available retractor is the self-retaining type.
These instruments are not hand-held and, therefore, leave free both
hands of the surgeon to perform other operating tasks. However,
these retractors are fabricated of metal, and as such are heavy and
may damage the soft tissue simply by the weight alone unless fixed
or supported in some way. For brain surgery they require fixation
to the bone of the skull either by clamping, which may be unstable,
or by drilling another hole into the skull and screwing a fixation
post into the bone. These retraction devices, like the hand-held
retraction device described above, also retract only one lip or
side of a wound. Their cost ranges typically from about $300.000 to
$1,000.00 for each retractor.
BRIEF SUMMARY OF THE INVENTION
This invention involves a disposable, self-retaining brain and
delicate tissue retractor fitted with interchangeable disposable
blades which in general may be lined with a disposable protective
coating. The retractor is designed to retract both sides of an
incision and to be self-supporting so as to enable the surgeon to
use both hands free to perform other tasks of the operating
procedure. The retractor of the present invention is designed to be
low in cost and light in weight, and is further designed to
minimize any trauma which brain or other delicate tissue may
undergo with retraction.
Three specific embodiments of the present invention are described
herein. All the embodiments are designed to be molded of plastic
and contain arms on which disposable blades of various designs may
readily be mounted. The retractors contain means for adjusting and
locking the retractor blade separation and are of sufficiently low
weight so as to allow the resting of the retractor directly on the
soft tissue without providing additional support.
The retractor is designed to have disposable blades and to retract
both sides of an incision in varying amounts depending on the
operation requirements. By having disposable blades of various
sizes and shapes, the retractor may be used as a soft tissue
retractor for nearly any operation. In addition, one of the
disposable blades may be replaced with a tooth blade or a hook
which, by way of example, would hook to the skull at the edge of
the opening in the skull created for purposes of the operation. In
this manner the other blade would provide support for the brain and
retraction between the brain and the skull.
For most operations, a strip of gauze-like material, (e.g.,
"telfa") with adhesive on the reverse side is fastened to the soft
tissue side of the retractor blades and overlaps the plastic border
thereon by approximately one millimeter to protect the soft tissue
and to assist in absorbing fluids that may be secreted as a result
of the wound.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective of the retractor of the present invention
showing the locking device, the retractable blades and the telfa
pads thereon.
FIG. 2 is a top view of the retractor of FIG. 1 showing the locking
means in greater detail and indicating two of the many possible
lock positions for the arms of the retractor.
FIG. 3 is a side view of the retractor of FIG. 1 showing additional
detail in its structure.
FIG. 4 is a view of the retractor looking into the end of the
retractor arms with the arms set so as to achieve the minimum
retractor blade spacing.
FIG. 5 is a cross-sectional view of part of the retractor of FIG. 1
showing greater detail in the locking mechanism for the retractor
arms.
FIG. 6 is an end view of one of the retractor arms end blade
showing an alternate shape for a disposable blade and the location
of the pad of gauze-like material on the blade.
FIG. 7 is a side view of the blade and arm of FIG. 6 illustrating
the overlap of the gauze-like pad with respect to the
interchangeable blade.
FIG. 8 is a sketch illustrating the use of the retractor of FIG. 1
to retract or separate the walls of an incision in brain tissue to
enable the brain surgeon to reach tumors or blood clots deep within
the brain substance.
FIG. 9 is a perspective view of a hook which may be used in place
of one of the interchangeable blades of the retractor of FIG.
1.
FIG. 10 is a sketch illustrating the use of the retractor with the
hook of FIG. 9, whereby the hook engages the skull at the edge of
the skull opening and the blade of the retractor elevates the brain
away from the base of the skull so that the surgeon may reach blood
vessels and structures in that area.
FIG. 11 is a top view of an alternate embodiment of the present
invention, showing an alternate configuration and an alternate
means for adjusting the spacing between the retractor blades.
FIG. 12 is a side view of the alternate embodiment of FIG. 11.
FIG. 13 is a cross-sectional view of FIG. 12 taken along lines
13--13 of that figure.
FIG. 14 is a perspective view of a preferred embodiment with the
locking members snapped together in functional disposition.
FIG. 15 is a perspective view of the preferred embodiment of the
present invention as it would be molded of plastic.
FIG. 16 is a side view of the present invention soft tissue
retractor of FIG. 15.
FIG. 17 is a cross-sectional view of the preferred embodiment of
the soft tissue retractor taken along lines 17--17 of FIG. 15,
showing the manner in which the locking members are retained in
functional relationship to each other.
DETAILED DESCRIPTION OF THE INVENTION
The invention to be presently described in detail is a disposable,
self-retaining brain and delicate tissue retractor fitted with
interchangeable disposable blades lined with a disposable
protective coating. This retractor is designed to be low cost,
light in weight and to enable the surgeon to have both hands free
to perform other tasks in the operation. The retractor is designed
to minimize any trauma which brain or other delicate tissue may
undergo upon retraction, and is further designed to retract both
sides of an incision in soft tissue, or to elevate soft tissue away
from bone structure.
Now referring to FIG. 1, a perspective view of one embodiment of
the present invention soft tissue retractor may be seen. This
embodiment of the retractor is comprised of the assembly of four
separate molded parts. These parts are a molded ring 10 with
retractor blade arms 12, two interchangeable disposable retractor
blades 14, each of which slides into a mating groove in the ends of
the retractor blade arms, and a locking member 16 which locks ring
member 10 so as to achieve the desired separation in retractor
blades 14. The retractor blade arms 12 each contain finger grips
18, which the surgeon may use to vary the separation in the
retractor blades 14 prior to locking the retractor blades in
position by locking member 16. Also, illustrated in FIG. 1 are the
disposable protective covering 20 of the retractor blades, which
are generally used on the retractor of the present invention.
Now referring to FIG. 2, additional details of the retractor may be
seen. Retractor ring 10 contains a tongue member 30 which extends
into the opening between members 32. Tongue member 30 has a
plurality of holes 34 generally disposed in a radial direction of
ring 10 and equally spaced about the circular arc of tongue 30.
Members 32 also contain a plurality of holes 36 generally directed
in a radial direction of ring 10, and disposed in a circumferential
direction with the same spacing of holes 34 in tongue member
30.
Locking member 40 contains locking pins 42 which have the same
spacing as holes 34 and 36 of members 30 and 32 respectively.
Therefore, locking pins 42 may be inserted into holes 34 and 36
when some holes 34 of tongue member 30 are in line with the holes
36 in members 32 as shown in the cutaway sketch of FIG. 5. When so
positioned, the locking pins 42 lock tongue member 30 with respect
to members 32, thereby locking retractor arms 12 at a specific
separation and more importantly, lock interchangeable retractor
blades 14 at a fixed separation.
In the embodiment shown, locking member 40 contains three locking
pins 42 and members 32 contain three sets of holes 36 whereas
tongue member 30 conains a plurality of holes substantially
exceeding three in number, so that three holes of tongue member 30
will align with the holes 36 in members 32 for various separations
of retractable blades 14, thereby allowing the locking of the
blades 14 by locking member 40 at various distances of
separation.
Shown in phantom of FIG. 2 is the position of the retractor arms 12
for minimum separation of the retractor blades 14. It may be seen
that the retractor arms 12 do not come together in this position,
but are disposed in a substantially parallel position with a
substantial separation therebetween. However, the retractor blades
14 are substantially in contact when the retractor arms 12 are so
located. This is well illustrated in FIG. 4 where it may be seen
that because of the angle or bend 44 in the retractor blades 14, a
large portion of the retractor blades 14 generally, indicated by
the numeral 46, is in contact with or in close proximity to the
other retractor blade. Also illustrated in FIG. 4 is the separation
in the retractor arms 12 when the retractor blades 14 are in close
proximity as just described.
FIG. 4 further illustrates the use of the telfa pads 50 on the
outer surfaces of the retractor blades. It may be seen that in
general the gauze-like pads 50 will extend from approximately the
angle 44 in the retractor blades 14 to slightly beyond the lower
edge of the retractor blades 14, so as to provide an overlap of
padding 52 to curve around the lower end of the retractor blades
and to prevent damage to tissue by the end of the blades. The pad
50 also extends in a direction parallel to the retractor arms 12 so
as to slightly overlap the edges of the retractor blades 14 again
for the purposes of preventing injury to the tissue by the edges of
the retractor blades 14. This may be seen generally in FIGS. 1, 2,
3, 7 and 12, generally indicated by the numeral 52. In the
preferred embodiment, pad 50 would be provided with an adhesive
backing so that it would naturally adhere to the surfaces of the
retractor blades 14 in the desired position. In alternative
embodiments, pad 50 might be in the shape of an envelope so as to
substantially fully enclose the lower portion of the retractor
blades 14, fully protecting the wound from contact with retractor
blades 14 and perhaps retain in position on the retractor blades by
adhesive backing, appropriately placed.
Referring to FIG. 3, a side view of the retractor of FIG. 1 may be
seen. This figure illustrates the generally planar character of
ring 10 and retractor arms 12 and the nature of the protrusion
which forms the finger grips 18. Also shown in this figure is the
generally overlapping nature of telfa pad 50 at the edges of the
retractor blade 14 indicated generally by the areas 54 of the telfa
pad. In general, the underside of arms 12 and ring 10, generally
indicated by surface 60, will rest on and be supported by an area
of the body surrounding the incision in which retractor blades 14
have been inserted. The generally planar character of retractor
arms 12 and ring 10 is suitable for most operations and, therefore,
constitutes the form of the preferred embodiment. However, it is to
be understood that arms 12 and ring 10 can be given other shapes so
as to generally conform to the contours of the areas of the body
and operations being performed.
FIG. 6 shows an alternate shape for retractor blade 14. This blade
is similar in shape to the blades shown in FIG. 4 but does not have
the angle 44. Such a blade might be used in conjunction with the
retractor of FIG. 1 to provide a wider retraction at the mouth of
the incision than at the base of the incision. At a further
alternative, the slots in the end of the retractor arms 12 in which
the retractor blades 14 fit may be substantially vertical when
viewed as shown in FIG. 4, rather than inclined as shown in that
FIG. In such a case, retractor blades such as those shown in FIG. 6
would project substantially parallel to each other when mounted to
the retractor arms 12 and would allow locking of the retractor
blades at greater separations than possible with the configuration
of FIG. 4, though such blades would have a substantially greater
minimum separation than is possible with the configuration of FIG.
4. It is to be understood that the details of the manner in which
retractor blades 14 are attached to the retractor arms 12 may be
varied without departing from the spirit and scope of the present
invention. Similarly, the blades themselves may be varied so as to
be adapted for use in various surgical procedures. By way of
example, in the preferred embodiment, interchangeable retractor
blades of various lengths, widths, angles, offsets or curvatures
would be made available for use with the same retractor, so as to
make that retractor useful in many varied types of operation. In
general, the retractor blades and the retractor body would be sold
independently in presterilized packages so that only the package
containing the desired blades need be opened for a specific
operation, and only those blades and the retractor body need be
disposed of after the operation.
FIG. 7 is a side view of the retractor arm 12 with a retractor
blade 14 mounted thereon and a telfa pad 50 attached to the
retractor blade. It may be seen that the pad 50 is somewhat larger
than the retractor blade 14 so as to overlap both the edges 54 and
the bottom 52 of the retractor blade 14, presenting to the wound a
fully padded and protected retractor blade.
FIG. 8 is a sketch illustrating the use of the present invention
retractor in brain surgery. As shown in the FIG., the brain is
exposed by drilling six holes 60 in the skull and slicing the skull
so as to interconnect the holes 60 to make removeable an area of
the skull 64 defined by the holes. A portion of the scalp between
two holes is not severed so that the removeable portion of the
scalp 64 may be pivoted on the flap the brain scalp 66 and made to
rest on an adjacent area of the head to expose the desired area.
This exposes the dura mater which envelopes the brain and is
external to the arachnoid and pia mater. In such an operation it is
often necessary to incise through brain tissue and retract it aside
to reach for tumors or blood clots deep within the brain substance.
To do this an incision is first made and then the retractor of the
present invention is used to separate the brain tissue at the
incision so as to make accessable tissue deep within the brain
substance. The retractor may be put in place by removing locking
member 40, squeezing on finger grips 18 so as to bring the
retractor blades 14 into close proximity as shown in FIG. 4, and
inserting the retractor 14 into the incision. Because the retractor
blades 14 are interchangeable, the size and shape of the blade may
be selected depending on the requirements of the particular
operation and the nature of the incision which has been made. Once
the blades are inserted in the incision, the brain tissue may be
retracted by lessening the pressure applied to the finger grips 18,
thereby allowing ring 10 to partially spring open forcing retractor
blades 14 to move away from each other and to open the incision
made in the brain. When the desired opening is obtained, locking
member 40 may then be inserted so as to lock the ring 12 in a fixed
position so that finger pressure is no longer required on finger
grips 18 to maintain the desired separation in retractor blades 14.
Although ring member 10 may only be locked in certain specific
positions, a sufficient number of locked positions may be provided
by the plurality of holes 30 (FIG. 2) so as to achieve
substantially all desired retractor settings. Also, it is to be
understood that means for locking the retractor other than that
shown in detail in FIGS. 2 and 5 may be provided. By way of
example, member 40 might be designed to have only one or two
locking pins 42 and members 32 might have a plurality of holes 36
equal in number to one more or one less than the number of holes in
tongue member 30, thereby providing a vernier adjustment or
selection of the retractor blade spacing by inserting locking
member 40 into one of the possible hole combinations. This and
other locking means may readily be adapted for use with the
retractor of the present invention by anyone skilled in the
mechanical arts.
The retractor of the present invention is sufficiently light in
weight that it requires no fixation to the body of the patient,
other than that which naturally arises from the location of the
retractor blade in the incision while the soft tissue is retracted.
Furthermore, the retractor need not rest on or be supported by bone
structure. By way of example, as shown in FIG. 8, the retractor may
rest upon and be supported by the dura covering the brain without
fear of injury to either the dura or the brain structure
thereunder. Therefore, separate holes in the skull for purposes of
anchoring the retractor are not required, nor is the surgeon
required to use one hand for operating the retractor once the
retractor is properly set. Furthermore, since the retractor may
rest on the dura, the retractor physically may be relatively small
and, therefore, need not needlessly encumber the operating
area.
In some operations it is necessary to elevate the brain from the
floor of the skull by retraction in order to reach the blood
vessels and structures beneath the brain. For such purposes, one of
the retractor blades may be configured as a hook-like member as
shown in FIG. 9. (Though the blades heretofore described have been
substantially flat blades, the term blade as used herein is used in
the general sense to include, by way of example, blades of various
shapes and curvatures, and to include hooks and hook members, as
are about to be described herein.) In this figure, hook member 70
contains hook 72 and mounting surfaces 74 which make it
interchangeable with the blades 14 of the retractor variously
depicted in FIGS. 1 through 8. Hook member 70 may be used in
conjunction with one of the retractor blades 14 in a retractor to
elevate the brain as shown in FIG. 10. In this figure, as opening
has been made in the side of the skull so as to provide access to
the base of the brain. Retractor blade 14 is then inserted beneath
the brain 76 with hook members 70 hooking over the edge of the
opening in the skull 78, thereby allowing retraction of the brain
76 with respect to the skull 78 to lift the brain from the base of
the skull 78 and provide access to the floor of the skull in order
to reach the blood vessels and other structures there located.
FIGS. 11 and 12 present a top view and a side view of an alternate
embodiment of the present invention. In this embodiment, the
retractor blades 14 may be substantially the same as the retractor
blades in the embodiment pictured in FIG. 1. As in that embodiment,
the blades of the embodiment shown in FIGS. 11 and 12 are also
removeable and blades or hooks of various designs may readily be
slipped in place in the ends of retractor arms 80. The retractor
arms of this embodiment form a basic "V" shape with the structure
in the vicinity of the apex of the "V" providing the required
elasticity to encourage the retractor arms 80 to a fully separated
position. Finger grips 82 are similar in function to finger grips
18 of the embodiment shown in FIG. 1, and provide a means for
changing the separation of the retractor blades 14.
Locking member 84 may be used to lock the retractor blades 14 at
various separations by the placement of lock 84 at any of a
plurality of possible positions along the retractor arms 80.
Locking member 84 is shown in FIG. 11 in a position to lock the
retractor arms 80 in the position for maximum retractor blade 14
spacing. Shown in phantom in that figure is an alternate location
for locking member 84, which locks retractor arms in a position for
a smaller retractor blade spacing. Additional retractor blade
spacings may be obtained either by providing more numerous
positions for locking member 84 or by providing a selection of
locking members 84 which may be used so as to achieve virtually any
desired retractor blade 14 spacing.
FIG. 13 presents a cross-section of the retractor of FIGS. 11 and
12 taken on lines 13-13 of FIG. 12. This cross-section shows
further details in the structure of locking member 84 and of
retractor arms 80 in the regions of the various locking member
positions. Retractor arms 80 have a generally circular
cross-section in the locking area with "V" notches 86 in each arm
80 disposed in a generally outward facing direction. Locking member
84 contains hook-like projections 88 which, when in position,
retain arms 80 with respect to locking member 84. By applying
pressure on finger grips 82 (FIG. 11), the retractor arms 80 may be
encouraged into closer proximity to each other, thereby allowing
the removal or change of locking member 84 to a new locking
position. Further integrity in the locking action between locking
member 84 and the retractor arms 80 is provided by the contouring
of the inner surface of locking member 84 so as to mate with the
surfaces of notches 86 in the retractor arms 80.
Now referring to FIG. 14, a perspective view of a preferred
embodiment of the present invention may be seen. This embodiment of
the invention consists of body member 100 with two arms 102,
extending therefrom in side by side relationship and each having a
replaceable retractor blade 104 attached to the end thereof. The
arrangement of arms 102 and the manner in which replaceable blades
104 attach thereto is the same as in the embodiments previously
disclosed herein, particularly the embodiment shown in FIGS. 1
through 4. Body member 100 is in the form of a split ring having a
flexible portion 106 between arms 102 and further having mating
locking members 108 and 109 adjacent to the split in body member
100. As molded, the locking members 108 and 109 are disposed in a
non-functional relation as shown in FIG. 15, and are subsequently
elastically encouraged to the functional relationship shown in FIG.
14. In this position, the teeth 107 of the locking members 108 and
109 are elastically encouraged into engagement and, as a result of
this engagement, provide a means of locking the retractor blades
104 in the desired separation.
The body member 100 is molded of plastic material in the shape
shown in FIG. 15. As previously described, locking members 108 and
109 are disposed in a non-functional relationship but body member
100 is intentionally designed and fabricated to have sufficient
elastic properties so that locking members 108 and 109 may be
elastically deformed to their functional disposition shown in FIG.
14. It is to be also noted in FIG. 15 that body member 100 is
molded with arms 102 in a substantially converging orientation so
that when retractor blades 104 are mounted thereto, as was shown in
FIG. 4 for the retractor blades 14 pictured therein, the arms 102
are elastically urged into substantially a parallel relationship.
In this manner, the elastic area 106 between arms 102 is
elastically encouraging retractor blades 104 into closer proximity
to each other even for little or substantially no initial retractor
blade separation. Of course, as the soft tissue retractor is
normally disposed in an incision in soft tissue, the normal
pressure of the soft tissue on retractor blades 104 also encourages
the retractor blades into lesser separation. Consequently, locking
members 108 and 109 need not provide a bilateral locking action,
but need only provide a unilateral action so as to prevent
retractor blades 104 from moving into lesser separations. To
accomplish this, the teeth 107 of the locking members 108 and 109
are inclined in the manner shown in FIGS. 14 and 15 so that they
provide the desired unilateral locking action but are free to slip
over each other in the opposite direction to adjust to and lock
retractor blades 104 at greater separations.
Body member 100 contains finger grips 110 which extend upward from
body member 100. By applying finger pressure between these finger
grips 100, the retractor blades 104 may be moved into greater
distances of separation and locked at any of a number of
separations by the action of the teeth 107 on locking members 108
and 109. Also protruding upward are the release fingers 112, one of
which extends upward from the end of a locking member 108 and the
other from the end of locking member 109. To release the locking
members 108 and 109 so that retractor blades 104 may be moved to
lesser separations, finger pressure may be applied to the release
fingers 112 so as to elastically encourage locking members 108 and
109 into separation, thereby allowing the translation of the
locking members with respect to each other in a direction normally
prevented by the engagement of the teeth thereof.
Now referring to FIG. 16, a side view of this preferred embodiment
of the present invention soft tissue retractor may be seen. As was
previously described in regard to previously disclosed embodiments,
body member 100 is a substantially flat member with the only
substantial downward protrusions being the replaceable retractor
blades 104. Since the soft tissue retractor will normally be molded
of a light weight material and in particular a light weight plastic
material, the substantially flat bottom surface of body member 100
allows the soft tissue retractor to lie flat on an area of the body
adjacent to the incision without additional anchoring or support.
Also shown in this figure are the finger grips 110 and the release
fingers 112, which are the only substantial protrusions above the
top surface of body member 100, thereby providing a minimum of
obstruction and encumbrance of the operating region.
Now referring to FIG. 17, a cross-section of locking members 108
taken along lines 17-17 of FIG. 15 may be seen. In this figure, it
may be seen that locking members 108 and 109 have mating toothed
surfaces substantially in the form of a tongue and groove with the
teeth 107 located on the end of the tongue and in the bottom of the
groove. This arrangement tends to retain locking members 108 and
109 in functional disposition and to prevent their lateral
displacement and return to the molded position shown in FIG. 15,
particularly with finger pressure is applied to finger grips 110 or
release fingers 112.
In this last embodiment, which is the preferred embodiment, the
body member 100 elastically encourages retractor blades 104 to
lesser separations and the locking members 108 and 109 act to
prevent the movement of retractor blades 104 to such lesser
separations. In this manner, any slippage or failure of the locking
members 108 and 109 result in the movement of the retractor blades
104 to lesser separations, that is, to the closed position, as a
result of both the elastic deflection of the elastic member 106 and
the normal pressure that the wound would apply to the retractor
blades 104. This movement, that is the movement of the retractor
blades so as to close the wound, upon the unlikely occurrence of
the failure in the locking member 108 and 109 to properly perform,
would in most operations be the desired occurrence. This is in
contrast to the characteristics of the two specific embodiments
previously described, both of which are elastically encouraged to
the open position, that is to greater separations of the retractor
blades 104, should a malfunction of the locking mechanism
occur.
The soft tissue retractor of the present invention reduces the
trauma experienced during the operation over that experienced by
using the prior art retractors. In addition to the trauma reducing
effect of the gauze pads, the more equal distribution of pressure
around the incision, because of equal retraction on both sides of
the incision rather than the unilateral retraction characteristic
of the prior art retractors, has a substantial trauma reducing
effect. Also, it is easier to periodically loosen the present
invention retractor during the operation which also has a trauma
reducing effect.
The soft tissue retractor of the presnt invention may be molded of
any of a number of plastics, since many plastics have sufficient
strength and elasticity for such purposes and yet are sufficiently
light to yield a durable and useful soft tissue retractor which
does not require anchoring or support. Though a plastic having the
capability of maintaining its properties when immersed in boiling
water would allow sterilization of the soft tissue retractor in
boiling water, such a temperature capability in the plastic used is
not required, as other means of sterilization are commonly used for
such equipment. By way of example, plastic forceps and other
instruments are commonly sterilized in an ethylene oxide atmosphere
at normal temperatures, thereby providing adequate sterilization
without temperature elevation. Consequently, plastic such as
polypropylene and polyethylene are suitable for such purposes
because of their light weight, moldability, strength and physical
integrity. Also of particular interest for use in the present
invention is polystyrene, which though havng a relatively low heat
resistance, is an inexpensive material which is easily molded and
readily sterilized in an oxidizing atmosphere.
It is to be understood that the three embodiments of the present
invention described herein in detail are presented merely for
purposes of illustration, and having now described the details of
these embodiments, one skilled in the art of surgical devices could
readily construct soft tissue retractors of other designs having
the invented features of the herein described soft tissue
retractors. By way of example, flexible member 106 in FIGS. 14 and
15 might be replaced by a pivot, thereby making body member 100
into two pieces and allowing the pressure of the soft tissue to
encourage retractor blades 104 into lesser separations should the
locking device fail to properly perform. Similarly, body member
100, whether one piece or two as just described, might be curved,
bent or have other shapes substantially different from the flat
ring like shape shown in FIG. 14 and FIG. 15. Also various other
locking devices may be used in place of the locking devices
disclosed herein. These and other variations of the present
invention may become particularly useful in specific types of
operations wherein a specific configuration or specific locking
method is particularly desired.
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