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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to structure for supporting a surgical instrument,
such as an endoscope, and more particularly to such structure which
provides for repositioning of the instrument during surgery without
stressing an incision through which the instrument extends.
2. Related Art
Laparoscopic surgery is a procedure in which surgical instruments and a
viewing scope, referred to generally as an endoscope and more specifically
as a laparoscope, are inserted through respective small puncture wounds or
incisions into the abdominal cavity of a patient. A small video camera is
attached to the laparoscope and connected to a television monitor for
viewing the procedure.
The instruments and the laparoscope are inserted through cannulae which are
first inserted through the incisions. Cannulae are hollow tubes with gas
valves. The cannulae are left in the puncture wounds throughout the
procedure. This allows the instruments and scope to be removed and
reinserted as necessary.
To aid in visualizing the intraabdominal structures, gas is inserted
through one of the cannulae to raise the abdominal wall. Seals are
required at the exit points of the scope and instruments to prevent the
gas from escaping.
The viewing laparoscope is inserted through a cannula which is usually
inserted through an incision made in the umbilicus. The scope is then
directed toward the pelvis for pelvic surgery or toward the liver for
gallbladder surgery.
Throughout the procedure it is necessary for the surgeon, assistant
surgeon, or a scrub nurse to hold the scope and direct it at the target of
the surgery. It is constantly being repositioned to obtain the best view.
This process ties up one hand of the surgeon or assistant surgeon, if
either holds the scope. The scrub nurses also have other tasks to perform,
and holding the scope interferes with performing these tasks. It is also
difficult for the surgeon to direct others to position the scope for the
best view. When the scope is not held by the surgeon, it is often
misdirected.
The support of a laparoscope has been provided through the use of robotic
retractors. Retractors hold instruments in fixed positions, such as for
holding an incision open to allow a surgeon access to the underlying body
parts. The retractors are fixedly clamped to a mechanical skeleton. This
skeleton has also been used to hold a laparoscope in a fixed position.
When it is desired to move the scope, the clamp must be readjusted, and
also the skeleton linkages must usually also be adjusted to accommodate a
change in angle of insertion of the laparoscope.
An apparatus that accommodates changes more readily is a robot-like arm
having ball joints next to an instrument holder. This apparatus is sold
under the proprietary name The Leonard Arm by Leonard Medical, Inc. of
Huntingdon Valley, Penn., and is described in U.S. Pat. No. 4,863,133
issued to Bonnell. Two articulating arms are used to couple an instrument
clamp to the operating table rail. A vacuum supply is used to frictionally
hold the joints. Three joints provide three degrees of freedom of
movement. When not freely moveable, manual force on the instrument clamp
is sufficient to reposition the instrument.
The invention of Bonnell is intended as a general-purpose instrument
holding apparatus. As such it is up to the user to control movement of the
instrument supported on the apparatus, since the axes of movement are
independent of and spaced from the patient, except for ball joints next to
the instrument holder. Further, this apparatus presents two arms that
extend upwardly over the operating table which interfere with access to
the patient by attendants, and requires a dedicated vacuum source in the
operating room.
A less imposing and more technically sophisticated robotic arm that is
commercially available is sold under the name AESOP by Computer Motion,
Inc. of Goleta, Calif. This arm has servo-operated joints with
computer-controlled motion based on a multipedal foot-operated input
device. This device has articulation about axes that are also spaced from
the endoscope, thereby requiring very careful movement control by the
surgeon in order to avoid stressing the tissue adjacent the laparoscope
incision. Further, the computer used to control movement makes the system
very expensive to produce.
A less expensive manual apparatus is described in U.S. Pat. No. 4,573,452
issued to Greenberg. A rigid metal ring that surrounds the incision area
is mounted above the table. A vertical control arm is mounted on a
ball-and-socket joint along the metal ring. A tensionable cable-like
component connects the top of the control arm to a laparoscope holder.
After initial placement of the holder, the cable-like component is
secured, after which movement of the laparoscope is achieved by pivoting
the control arm about the ball and socket joint. It is suggested that the
ball and socket joint be coplanar with the incision through which the
laparoscope extends.
The Greenberg apparatus requires the use of the ring which is positioned
over the patient. This ring, though of low profile can interfere with
surgical procedures. Further, the laparoscope is pivoted about the
ball-and-socket joint which is located along the ring. Thus, except for
movement of the scope about the axis that intersects both the incision and
joint, the laparoscope moves from the incision, causing stress on the
tissue around the incision. Significant changes in position of the scope
requires release and repositioning of the cable-like component.
SUMMARY OF THE INVENTION
The present invention overcomes disadvantages of these prior art devices.
Generally, the present invention provides an endoscope holder apparatus
that provides for adjustment of the endoscope, once it is positioned
through an incision, without stressing the tissue surrounding the
incision.
More specifically, the present invention provides an endoscope holder
apparatus having a base fixedly mountable on an external frame, such as a
surgical table. A holder is fixedly mountable to the endoscope for
supporting the endoscope along a longitudinal scope axis that extends
through an incision region. An articulating assembly couples the base to
the holder for limiting movement of the holder to motion about first and
second non-parallel axes that pass through the incision region.
The preferred embodiment of the invention includes a first clamp fixedly
mountable at a position along a mounting rail of a surgical table. A
second clamp fixedly secures a first arm in a selected vertical position
relative to the first clamp and in a selected orientation about a vertical
first axis. A third clamp, having a clamp body is mounted on the upper end
of the first arm for fixedly securing the clamp body about a horizontal
second axis.
A first manually operable friction pivot joint is mounted on the third
clamp for pivoting a second arm about a third axis that is orthogonal to
the first axis when the third axis is horizontal. A fourth clamp fixedly
secures the second arm in a selected position along the third axis.
A holder is fixedly mountable to an endoscope for holding the endoscope
along a scope axis that intersects the third axis at a pivot point.
Finally, a second manually operable friction pivot joint is mounted on an
end of the second arm so that it is spaced from the third clamp. The
second pivot joint is selectively manually attached to the holder for
pivoting the holder relative to the second arm about a fourth axis that is
orthogonal to and intersects the third axis at the pivot point.
The pivot joints allow for manually pivoting an endoscope supported in the
holder about the pivot point when the first, second, third and fourth
clamps are secured. By having the two adjustable pivot axes intersect the
scope axis in the incision region, any movement of the scope will result
in minimal movement in the incision region. Since the incision is
typically as small as possible, this invention thus assures that there is
no excessive stress on the tissues surrounding the incision. Further, in
its preferred form in which the pivots are frictionally set, a supported
endoscope is held in position by the apparatus when the attending surgeon
releases hold of it. Further, the surgeon can reposition it manually by
overcoming the frictional forces. Those forces are adjustable to
accommodate supporting endoscopes having different weights.
These and other features and advantages of the present invention will be
apparent from the preferred embodiment described in the following detailed
description and illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a an isometric view of an apparatus made according to the
invention.
FIG. 2 is a cross section of a first frictional pivot joint of the
apparatus of FIG. 1 taken along a vertical plane containing the pivot
axis.
FIG. 3 is a cross section taken along line 3--3 in FIG. 2.
FIG. 4 is an enlarged isometric view of a second frictional pivot joint and
endoscope holder of the apparatus of FIG. 1.
FIG. 5 is a cross section of the joint and holder of FIG. 4 taken through
the pivot axis of the joint.
FIG. 6 is an isometric view of second embodiments of the friction vertical
pivot joint and scope holder of the embodiment of FIG. 1, shown with the
scope holder attached to a cannula.
FIG. 7 is a break-away view of the pivot joint of the embodiment of FIG. 6.
FIG. 8 is a partial break-away view of the scope holder of FIG. 6 showing
the arm-lock apparatus for supporting the scope holder relative to an arm
extending from the pivot joint.
FIG. 9 is a break-away view of a portion of the scope holder of FIG. 8
showing the arm-lock apparatus in a release position.
FIG. 10 is an isometric view of the scope holder of FIG. 6 separated from
the support arm and cannula.
FIG. 11 is a partial break-away view of the scope holder of FIG. 10
supporting the shaft of a laparoscope.
FIG. 12 is a view of the scope holder of FIG. 10 with a wing for supporting
a cannula partially broken away.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 1, an apparatus 10 is shown for supporting a
conventional laparoscope 12 relative to an operating table having an
equipment mounting rail 14. The term endoscope as used herein also refers
to associated equipment, such as a cannula 16. The cannula has a gas valve
18 for preventing the leakage of gas from around the shaft of the
laparoscope. The tubular end of the cannula extends along a scope axis 20
through an incision 22 located in what is generally referred to as an
incision region 24 of a patient 26.
The laparoscope includes an eyepiece 28 mounted on the end of a viewing
tube 30 which extends along axis 20 to an end 30a. Light received from a
light source is transmitted to tube 30 via an optical cable 31. The light
is directed out of tube end 30a for illuminating the body cavity. The body
cavity is then viewed by a video camera 32 connected to a monitor by a
connecting cable 34.
Apparatus 10 includes a base 36 having a base clamp 38 with a jaw 40.
Manual turning of a lever 42 screws a clamp shaft 44 for moving the jaw
relative to a base member 46. A guide pin 48 and shaft 44 maintain the
orientation of the jaw relative to rail 14.
A vertical shaft 50 is rotatable about and shiftable along a first vertical
axis 52 in an elevation clamp 54 securable by a handle 56. At the top of
shaft 50 is a tilt clamp 58, including a fixed member 60 fixedly extending
upwardly from the shaft, and a pair of jaws 61 and 62 formed in a lower
support body 64. Jaws 61 and 62 are secured on fixed member 60 by a lever
66 that is used to drive a clamp shaft 68. Clamp 58 is used to secure
lower support body 64 about a first horizontal axis 70 defined by shaft
68.
As shown more clearly in FIGS. 2 and 3, lower support body 64 and an upper
support body 72 form part of a first frictional pivot joint 74, also
referred to as articulating means, providing pivoting about a pivot axis
76. When lower support body 64 is in an upright position, as shown in the
figures, axis 76 is also horizontal, and therefore is referred to as a
horizontal axis even though it is not always horizontal.
Support body 64 includes two of upstanding, spaced-apart shoulders 64a and
64b. These shoulders have respective bores 64c and 64d sized to slidingly
receive a solid shaft element 78 for rotation about axis 76. Element 78 is
also generally referred to as a movement member.
A friction lock assembly 80 selectively fixes the position of shaft element
78 relative to lower support body 64. Assembly 80 includes a shaft
extension 82 fixedly attached to shaft element 78 by a threaded bolt 84.
Extension 82 has an eccentric arm 82a that extends adjacent to face 64e.
A bore 86 extends through arm 82a along an axis that is parallel with pivot
axis 76. Bore 86 is sized to receive a compression spring 88 that seats
against a shoulder 82b formed by a reduced-diameter bore portion 86a. The
end of spring 88 adjacent to face 64e is seated on a ring or flange 90a of
a pin 90. In the position shown in FIG. 2, one end of pin 90 extends
freely into one of a series of cavities 94 extending into support body 64
through face 64e. Cavities 94 are distributed circumferentially around
shaft element 78.
The opposite end of pin 90 extends through reduced-diameter bore portion
86a and is fixedly attached to a friction release knob 96. Knob 96
includes a leg 96a that extends along the side of extension 82. Leg 96a
has a length that is slightly longer than the length of pin 90 that
extends into cavity 94.
When pin 90 extends into cavity 94, as shown in FIG. 2, the position of
shaft element 78 is fixed relative to lower support body 64. When knob 96
and attached pin 90 are manually pulled away from face 64e, as shown by
the axial arrow, shaft element 78 is freely pivotable with respect to body
64. Knob 96 may be rotated about pin 90 when the pin is retracted from a
cavity, positioning leg 96a on the outer end of extension 82, as shown by
the position of the knob in phantom lines. This retains the pin out of the
cavities, leaving shaft element 78 to freely rotate relative to body 64.
When it is desired to fix the position of the shaft element relative to
the lower support body, it is simply necessary to rotate leg 96a until it
is oriented away from the end of the extension. The shaft extension is
then rotated as needed in order to align pin 90 with a cavity 94. Spring
88 then drives the end of the pin into the cavity, again locking the
rotational position of the shaft element relative to the lower support
body.
Upper support body 72 has a lower end 72a positioned between shoulders 64a
and 64b. A bore 72b coaxial with bores 64c and 64d, slidingly receives
shaft element 78. Both the upper and lower support bodies thus pivot with
respect to each other and with respect to the shaft element (subject to
the operation of lock assembly 80).
A friction assembly 100, also referred to as movement-resisting means, is
mounted in a bore 102 in upper support body 72 for applying friction for
resisting pivoting of body 72 relative to shaft element 78. Bore 102 has
an upper end 102a that is open and threaded, and a lower end 102b that is
open to shaft element 78. A saddle-shaped friction bushing 104 conforms to
and rides on shaft element 78 in bore 102. A compression spring 106 is
positioned in bore 102 between bushing 104 and a spring-tension adjustment
screw 108.
Screw 108 is threadedly received in upper end 102a of bore 102 and has an
externally extending hexagonal knob 108a used to turn screw 108, and
thereby adjust the force of spring 106 on bushing 104. This in turn
adjusts the friction between bushing 104 and shaft element 78.
An upper end 72c of the upper support body has a channel 110 that extends
parallel to pivot axis 76. Channel 110 is cylindrical. A cross bar 112,
generally conforming to the shape of channel 110 except for an upper flat
edge 112a and a lower groove 112b, extends slidingly through the channel.
Bar 112 is selectively secured in position relative to body 72 by a clamp
in the form of a lock screw 114 that is threadedly received in a vertical
bore 116 that extends into channel 110. A pivotable handle 118 is used to
manipulate screw 114. A pin 115 is fixed in a reduced diameter bore in
body 72 such that one end of the pin extends into groove 112b of bar 112.
This prevents bar 112 from turning in channel 110, but allows movement of
the bar through the channel.
One end of bar 112 extends through body 72, as shown in FIG. 2. The other
end supports a second friction joint 120 that provides for pivoting about
a vertical pivot axis 122 that is orthogonal to pivot axis 76, and
intersects axis 76 at a point 124. As will be seen, point 124 is in
incision region 24, and preferably also is on scope axis 20. However, the
advantages of the present invention are substantially obtained so long as
axes 76 and 122 both pass through the incision region, whether or not they
intersect.
Joint 120 includes a joint body 126 mounted to bar 112 by a pin 128 passing
through the body and a bar extension 112a extending into a cavity 130.
Spaced from cavity 130 is a vertical bore 132 having a wide upper section
132a, a narrow lower section 132b, and a tapered intermediate section
132c. A pivot shaft 134 is positioned in bore 132 and is sized and shaped
to generally conform to the lower end of bore section 132a, as well as
sections 132b and 132c, as shown. Shaft 134 rotates within the bore and
has a distal end 134a extending out from the bottom of bore 132. End 134a
extends fixedly into a conforming hole 136 in an elongate arm 137. Joint
120 thus provides pivoting of arm 137 about vertical pivot axis 122.
A compression spring 138 is disposed in bore 132 in contact with the top of
shaft 134. The force of the spring is controlled by adjustment of a screw
139 threadedly received in the top of upper bore section 132a. As with
screw 108, screw 139 has a hexagonal adjustment knob 139a engageable by a
wrench for rotating the screw. Since no weight is supported by joint 120,
only moderate spring pressure is required to hold scope holder 144 in
position. This frictional drag is readily overcome by manually applying a
minimum force to holder 144.
Arm 137 extends horizontally from axis 122 and has an end opposite from the
axis with a bore 140 that is open along one side, as is shown in FIG. 4.
This opening receives a threaded shank 142 of a quick-release scope holder
144. Holder 144 includes a main body 146 having a horizontal channel 148
in a top surface 146a. A connection knob 150 rotates on shank 142 for
joining holder 144 to arm 137. The arm has a bottom surface 137a that
conforms with channel 148, so that main body 146 is fixed in alignment
with arm 137 when holder 144 is attached to the end of the arm.
Body 146 also has a cannula passageway, not shown, extending along scope
axis 20. Axis 20 is at an angle A of 20.degree. from horizontal, and as
has been mentioned, extends through incision region 24, and preferably
intersects both axes 76 and 122 at point 124. Attached to body 146
opposite from point 124 is an annular gas seal 152 that seals the main
body relative to a cannula 16 supported therein. This keeps
intra-abdominal gas from escaping between the holder and the cannula. A
depth lock knob 154 is joined to a cam lock, not shown, that secures the
penetration position of the cannula.
A scope holder extension 156 is joined to main body 146. This extension is
preferably cone shaped, tapering toward the incision region. Extension 156
has a passageway 158, shown in FIG. 5 that conforms with the passageway in
the main body of the holder, and correspondingly extends along axis 20.
The extension is preferably long enough to extend through incision region
24. This means that horizontal axis 76 and vertical axis 122 extend
through the extension and point 124 is inside passageway 158, as shown in
the figure. Other suitable devices may also be used to connect apparatus
10 to an endoscope.
During initial setup, the position of base clamp 38 along operating side
rail 14 is selected so that cross bar 112 can be positioned close to the
patient without obstructing the operating procedure. A cannula 16 is
inserted into holder 144 and the cannula is inserted into the abdominal
cavity using standard techniques. If large areas of the abdomen are to be
visualized, it is important to do so prior to attaching holder 144 to arm
137.
The position of arm 137 is aligned with holder 144 by movement of arm 112
in channel 110, movement of shaft 50 in base 36, and movement of base 36
along rail 14. Base 36 is secured on the rail by tightening clamp 38. The
vertical position of shaft 50 is then secured by locking elevation clamp
54, and the position of the cross bar is secured by tightening lock screw
114. Holder 144 is then secured on the end of arm 137, as shown in FIG. 1.
If necessary, the angle of cross bar 112 relative to vertical shaft 50 may
be adjusted using tilt clamp 58. Clamp 58 should be loose when the
position of vertical shaft 50 is being set, since the angle of the cross
bar and the position of the cross bar relative to the patient affect the
position of the vertical shaft.
For ease of set up, when large movements are being made, knob 96 of the
friction lock assembly is pulled out and rotated so that leg 96a rests on
the outer face of the shaft extension, holding pin 90 out of cavities 94.
There is then no resistance to movement between lower and upper support
bodies 64 and 72. Lock assembly 80 thus disables friction assembly 100.
When the desired position of the upper support body is reached, knob 96 is
simply rotated back to its original position and shaft extension 82 is
rotated until pin 90 finds a cavity. Joint 74 is then a friction joint
that can be manipulated by applying a sufficient force to a laparoscope
held in holder 144.
During use, to move the angle of the scope and cannula through the
incision, the scope is grasped at a convenient location and moved. The
scope is only movable or articulatable about horizontal pivot axis 76 and
vertical pivot axis 122, both of which intersect at point 124 on scope
axis 20. In this preferred embodiment, then, the scope in essence only
pivots about point 124 once the other adjustment clamps are secured. As
has been mentioned, joints 74 and 120, also referred to as articulating
means, are friction joints and hold the scope in whatever position it is
moved to.
Also, since holder 144 is secured directly to the cannula, and not the
scope itself, the scope can be repositioned along scope axis 20 by sliding
the scope within the cannula. The scope may be removed from apparatus 10
for tip cleaning or x-ray clearance, by withdrawing the scope from the
cannula. The cannula remains in position, being held in holder 144. The
scope is thus readily reinserted at the same angular position it had prior
to removal.
FIGS. 6-12 illustrate a second embodiment preferably usable in place of
friction joint 120 and scope holder 144. This embodiment includes a
vertical axis pivoting friction joint 160 supporting a support arm 162
relative to a cross bar 164 equivalent to cross bar 112. Arm 162 supports
a scope holder 166 that is shown attached to a cannula 168.
Friction joint 160 is very similar to friction joint 120 except that it is
upside down and arm 162 extends upwardly away from the joint preferably at
an angle of 20.degree.. The support arm is thus parallel with scope axis
20.
As shown in FIG. 7, joint 160 includes a shaft 170 having an enlarged
portion 170a fixedly mounted in an arm base member 172. Shaft 170 also has
a reduced diameter portion 170b sized to be freely received in a tension
spring 174. Spring 174 is captured between a washer 176, supported on
shaft portion 170b against a shoulder formed by enlarged portion 170a, and
a tension adjustment screw 178. This screw is threadedly received in a
bore in a bar base member 180. As with joint 120, the resistance to
movement about vertical pivot axis 122 is controlling by adjusting the
tension on spring 174 with screw 178.
Referring now to FIGS. 8 and 9, holder 166 includes a support-arm lock
assembly 182 mounted in a holder body 184. A lock member 186 is mounted in
body 184 for sliding vertically a small distance in a slot, not shown.
Body 184 includes a channel 188 for slidingly receiving support arm 162. A
recess 190 in the top of the lock member conforms and is generally aligned
with channel 188, but is movable slightly upwardly into the channel by
action of a biasing spring 192. The upper end of spring 192 extends
upwardly into a bore in the lock member and has a lower end that rests in
the bottom of the lock member slot in body 184.
During normal use, the lock member is biased upwardly against a support arm
supported in channel 188, preventing movement of the support arm. When it
is desired to move the scope holder relative to the support arm, the upper
end of a lever arm 194 is squeezed toward the top of holder body 184, as
shown by the arrow in FIG. 9. Lever arm 194 pivots about a pin 196 mounted
on each side of the holder body. This forces a lower edge down against an
extension 186a of the lock member. This pushes the lock member down
against the force of spring 192, releasing the support arm in the channel.
The support arm is then free to be moved to a different position or to be
removed from the holder. When the lever arm is released, the lock member
reseats against the support arm, locking it in position.
In some cases it is desirable to apply friction to a laparoscope shaft to
prevent it from sliding inwardly through an associated cannula and to
prevent it from rotating. There are other cases in which it is desirable
to allow the laparoscope to be easily moved. Accordingly, and as shown
particularly in FIGS. 10 and 11, holder 166 also includes a laparoscope
friction assembly 200. This assembly includes a vertical slider 202 seated
in a vertical slot 204 in holder body 184. Slider 202 includes an
outwardly extending knob 202a at the upper end and has a concave surface
202b at its lower end. This lower surface is disposed in line with a
laparoscope channel 206 sized to freely receive the shaft 30 of a
laparoscope along axis 20. Slider 202 is biased downwardly toward channel
206 by a bias spring 208 seated in a corresponding bore, not shown, in the
upper end of the slider. The other end of the spring is seated against the
top surface of slot 204, as shown.
When the action of the spring is allowed to act on the slider, frictional
pressure is applied to a laparoscope shaft that is sufficient to hold the
shaft in longitudinal and rotational position. However, the friction is
preferably light enough to allow the laparoscope to be moved by manual
manipulation. Friction assembly 200 thus preferably does not function to
fixedly lock the scope shaft in position.
For those cases in which it is desired to leave the scope freely movable, a
friction defeat lever 210 is provided. Lever 210 is mounted in a slot 212
in the side of the holder body for pivoting about a pin 214. At the inside
lower edge of lever 210 is a finger 210a that is movable relative to
slider 202, as shown in FIG. 11. The side of the slider has a recess 216
in which finger 210a may be inserted after moving the slider upwardly in
slot 204 by manipulation of knob 202a. This then prevents the slider from
moving down against the scope shaft. The slider may be released by
pressing inwardly on the top of lever 210, and thereby disengaging finger
210a from recess 216.
Finally, holder 166 also preferably includes a cannula holding assembly,
such as assembly 220. There are different types of cannulas, and a
suitable holder can be readily designed to attach each type to holder 166.
The assembly shown is for holding a cannula having side slots or openings
in which engaging tabs may be inserted. More particularly, assembly 220
includes wings 222 and 224 positioned on opposite sides of holder body
184. A pivot rod 226 extends through body 184 for pivoting about a lateral
axis 228. The wings are suspended from the opposite ends of the pivot rod
by a cross pivot pin, such as pivot pin 230 associated with wing 224. The
pivot pins allow the bottom ends of the wings to pivot outwardly from the
holder body about transverse axes, such as axis 231. Each wing is biased
outwardly by a spring, not shown, captured in respective recesses in the
wing and holder body.
Further, the positions of the wings are controlled by movement of a
laterally extending thrust shaft 232 supported in the holder body. The
thrust shaft is itself laterally shiftable in position, generally parallel
with support-arm channel 188, by rotation of a threaded drive shaft 234.
Shaft 234 is rotated by manual rotation of an enlarged knob 236 mounted on
an exposed end. The middle section of the drive shaft is threadedly
received in a correspondingly threaded bore in thrust shaft 232. The drive
shaft is also positioned in a complementary slot in slider 202 and a bore
in the opposite side of holder body 184.
The bottom end of each wing has a corresponding outwardly extending tab,
such as tab 224a compatible with the cannula that it is designed to
engage. A flare pin, such as pin 238, extends from the inside surface of
the lower end of each wing. Knob 236 is rotated to extend tabs 222a and
224a toward a cannula to be attached. The wings are then pressed toward
the holder body and the tabs inserted in the corresponding slots of the
cannula. With the wings in this position, the flare pins seat in a tapered
groove, such as groove 184a. These grooves are deepest near the cannula.
As knob 236 is turned in the opposite direction to draw the cannula toward
the holder body, the wings are pushed away from the holder body as the
flare pins travel in the associated grooves. This further secures the
cannula to the holder. Additionally, as the cannula is drawn toward the
holder body, a projection 184b of the holder body extending around the
opening of scope shaft channel 206, as shown in FIG. 12, presses against
the cannula body. This binds the cannula in a grip between the tabs and
projection 184b.
Laparoscope holder 166 has an advantage over holder 144 in ease with which
it may be positioned on the support arm. That is, it is simply necessary
to grasp the top of the holder and squeezing lever 194 against holder body
184. Further, the scope itself, independently of the cannula, can be
selectively frictionally secured in the holder. When it is desired to free
the scope, simple lever and slide movements are all that are necessary to
defeat the function of the friction assembly.
Endoscope holder apparatus 10, with either embodiment of the scope holder,
has several beneficial features. The angle and linear position of the
scope is adjustable with one operator hand. There is (selectively, in the
second embodiment) no restriction to scope removal from or manipulation in
the cannula. The overall angular position of the scope and cannula is held
by friction controlled springs having adjustable compression.
The simplicity of the intersecting two-axis linkage avoids the need for
multi-joint arms that often interfere with scope angular movement and are
more difficult to set up and adjust. The friction joints avoid the need to
release and reapply locking mechanisms each time the scope is adjusted.
This is an activity that typically requires the use of two hands, one to
hold and position the scope, and the other to manipulate the lock
mechanisms. Where more than one joint or lock mechanism is involved,
adjustment is awkward and more time consuming.
Apparatus 10, being a mechanical linkage system, does not require a source
of positive or negative air pressure. Mechanisms based on such systems
must accordingly be controlled through conduit, valving and switches. The
added complexity of such systems is avoided in the preferred embodiments
of the present invention.
The two-axis mechanical geometry of the present invention also allows the
apparatus to be positioned close to a patient so that it does not
interfere with movement of the scope, other instruments or operating
personnel, or with viewing of the operating area by the operating
personnel.
Variations in form and detail may be made in the preferred embodiment of
the present invention without varying from the spirit and scope of the
invention as defined in the claims when construed according to applicable
legal principles. For instance, the purely mechanical assembly described
with reference to the preferred embodiment could be replaced with a
positive or negative air pressure system or a computer-controlled system
employing air or electricity driven servo motors. Other mechanical linkage
configurations could be designed which would provide the effect of nearly
intersecting axes. As has been mentioned, the various axes do not have to
truly intersect in order to obtain the benefits of the invention. The
preferred embodiment is thus provided for purposes of explanation and
illustration, but not limitation.
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