Note: Descriptions are shown in the official language in which they were submitted.
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IRRIGATION AND ASPIRATION SYRINGE
TECHNICAL FIELD
This invention relates to an irrigation and
aspiration syringe, and more particularly to such a
syringe having control grips on the syringe barrel and an
outer sleeve for one-handed operation.
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BACKGROUND ART
A cataract is a cloudiness or opacity which
develops in the lens of the eye which is normally
clear and transparent. A person with impaired vision
due to a cataract may have his vision improved
through a combination of cataract surgery and proper
corrective lenses.
An ophthalmologic surgeon may elect one of
several different surgical procedures for removing a
lens that has a cataract. Intracapsular-cataract
extraction is a technique for the removal of the
entire cataract, including its capsule, in one
piece. Extracapsular cataract extraction and
phacoemulsification and aspiration are two surgical
techniques that involve the removal of the opacified
portions of the lens, while the cle~ar posterior
capsule which was the original support for the lens
~- is left in place. In the extracapsular technique,
the clear capsule will provide support as well for
the implanted plastic intraocular lens. In this
fashion, the intraocular lens can be placed behind the
ir~s rather t~an supported on ~t or in front of
it. Current research suggests that this is a more
favorable position for an implant, both for optical
and for eye health reasons.
In the extracapsular cataract extraction
technique, an incision is made in the eye large
enough to deliver the nucleus of the lens
separately. The incision is then closed and
irrigation and aspiration are required to remove the
softer cortex or peripheral cataract portions. The
lens nucleus is frequently very hard and requires
removal by this planned extracapsular technique.
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However, if the lens nucleus is soft enough, the center of
the cataract called the nucleus can be emulsified with
ultrasound. The hardness of a lens nucleus which clinically
is usually related to the density or brunesence of the nucleus
determines whether a cataract can be emulsified or whether it
requires planned extraction. In the ultrasound technique, a
small incision of approximately three millimeters is made in
the front of the eye, and a very tiny needle connected to an
ultrasonic generator is inserted into the eye. The ultrasonic
generator vibrates the needle tip at up to 40,000 cycles per
second. This ultrasonic action cuts away and emulsifies the
cataract. The emulsified lens may then be withdrawn through
a regulated suction through the end of a needle.
Regardless of which extracapsular surgical technique of
1~ nucleus removal is employed, irrigation and aspiration is
required to remove the peripheral lens cataract (cortex).
Current medical instrumentation available for irrigation and
aspiration is either a conventional syringe or a sophisticated
mechanical irrigation and aspiration unit. The conventional
syringe requires two hands to operate, but there is often a
requirement in cataract surgery to have one-hand free for
other tasks. It is not considered safer convenient or
comfortable for a surgeon to use both hands for the operation
of the conventional syringe. The operation of mechanical
irrigation and aspiration units requires highly sophisticated
personnel and additional equipment such as a system to provide
a vacuum for the suction. The present state of the art
phacoemulsification instruments are expensive and the cost to
the patient for each use is significant, while the damage
potential to the eye in an inexperienced hand is great.
A need has thus arisen for an irrigation and aspiration
instrument which can be operated with a single hand in
surgery. In addition, a need has arisen for an irrigation
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and aspiration surqical device which is simpler to operate,
is useful in less technologically developed areas, and reduces
the risk of damage to the eye.
DISCLOSURE OF THE INVENTION
In accordance with an aspect of the invention there is
provided an irrigation and aspiration syringe comprising a
hollow cylindrical cartridge extending to a nozzle at one end
and an enlarged opening at the opposite end; means for
controlling the axial movement of said cartridge; a needle
secured to the nozzle and having a first passage in fluid
communication with the hollow chamber of the cylindrical
cartridge and a second passage for connection to a source of
irrigation fluid for irrigation; a plunger having a disk
dimensioned to closely engage and slide within the hollow
cylindrical cartridge, and a rod for controlling the movement
of the disk within said cartridge; an outer sleeve dimensioned
to receive said cartridge, said sleeve including an open end
for receiving the open end of said cartridge and means for
connecting said rod of said disk to the opposite end of said
sleeve; and means for controlling the axial movement of said
outer sleeve, whereby said means for controlling axial move-
ment of said cartridge and said means for controlling the
axial movement of said outer sleeve permit selective axial
movement of said outer sleeve relative to said hollow
cylindrical cartridge with one-hand while maintaining the
needel in the desired position for irrigation and aspiration,
movement of said sleeve along said cartridge to withdraw said
plunger from said cartridge creating a vacuum at said nozzle
end for aspirating material into said hollow chamber of said
3Q cartridge, movement of said sleeve along said cartridge to
move said plunger into said cartridge reducing the vacuum at
the nozzle to control the rate of aspiration.
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In accordance with the present invention, a compact irri-
gation and aspiration instrument is provided for one-handed
operation, particularly in extracapsular cataract surgery.
The improved irrigation and aspiration instrument includes a
syringe barrel having a first control grip extending upwardly
from the barrel, and a second control grip affixed to an outer
sleeve fitted over the barrel and attached to the plunger. A
needle is attached to the syringe having an opening at the
end of the needle for aspirating material through the needle
lQ into the barrel of the syringe. A vacuum may be produced by
the aspiration and irrigation instrument by using the control
grips with one-hand to slide the outer sleeve axially away
from the end of the barrel connected to the needle and thus
retract the plunger. The contents of the syringe may be
expelled upon removal of the instrument from the patient's
eye wi~h one-hand operation by using the control grips to
slide the sleeve axially toward the end of the barrel
connected to the needle. An irrigation solution is admitted
through an inlet port of a cylindrical sleeve surrounding the
2Q needle, the sleeve extending to a discharge opening near the
tip of the needle.
In another embodiment of the invention, a first control
grip extends upwardly from the barrel of the syringe, and an
outer sleeve surrounds the barrel and has a curved handle to
fit the palm of the hand and a second control grip along the
side of the sleeve opposite the first control grip on the
barrel. The syringe is opened to aspirate fluid by using the
first and second control grips with one-hand to withdraw the
plunger from the barrel.
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BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the presesnt
invention and its advantages will be apparent from the
following Detailed Description, taken in conjunction with
the accompanying drawings in which:
FIGURE 1 is a cross-sectional schematic view of a
human eye;
FIGURE 2 illustrates a conventional irrigation and
aspiration syringe in extracapsular cataract surgery;
FIGURE 3 is a magnified view of the needle of an
irrigation and aspiration syringe in use in cataract
surgery;
FIGURE 4 is a partially cut away side elevation view
of one embodiment of the present invention; and
FIGURE 5 is a partially cut away side elevation view
of an alternate embodiment of the present invention.
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DETAILED DESCRIPTION
FIGURE 1 illustrates a cross-sectional schematic
view of the human eye, generally iden~ified by the
reference numeral 10. The eye 10 is shown surrounded
in front by the upper lid 12 and lower lid 14. The
eye 10 may be viewed as consisting of a large sphere
16 with the segment of a smaller sphere, the cornea
18, in front.
The eye 10 is composed of three layers. The
first layer is the tough, white outer coat including
the cornea 18 and the sclera 20, which covers
approximately the posterior five-sixths of the
surface and extends to the external sheath of the
optic nerve 22. The middle layer is the choroid 24,
the thin, pigmented vascular coat of the eye
extending posteriorly to the optic nerve 22. The
third layer is the retina 26.
The iris 28 is the circular pigmented membrane
behind the cornea 18, and the iris 28 is perforated
by the pupil 30. The lens 32 is a double-convexed
normally transparent body held in place by an elastic
lens capsule 31, The aqueous humor 36 fills the
space between the cornea 18 in front and the lens 32
in the rear. The vitreous humor 38 is a clear,
jelly-like substance filling the space behind the
- lens 32.
FIGURE 2 illustrates the position of the
ophthalmologic surgeon's hands 50 in relation to a
conventional surgical aspiration syringe 52 and the
surgically draped patient 54. High magnification in
ophthalmologic microsurgery requires gr~at stability
and maximum proprioceptive control of the patient's
eye and head position at all times during surgery.
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The mid-air hand position required for the aspiration
technique with a conventional syringe 52 is a
precarious portion of extracapsular surgery. Two
hands are required to stabilize the aspiration
S syringe 52 within the patient's eye. The one hand
proximate the needle of the syringe S2 is necessary
for near control and patient proprioception, and the
other hand is necessary for applying suction and
occasionally reverse suction while irrigating and
aspirating the cortical cataractous material.
FIGURE 3 is a low magnification photograph of
the surgeon's view while performing the previously
described irrigation and aspiration technique
illustrated in FIGURE 2. A needle 60 connected to
the irrigation and aspiration syringe S2 is inserted
in an incision made on the edge of the cornea 18.
The tip of the needle 60 includes an outer sleeve
- portion 62 fitted about an inner cylindrical member
64 to allow the flow of a balanced intraocular
irrigation solution to irrigate the eye 10. An
opening 66 is formed in the inner member 64 for
aspirating the cortical cataractous material from the
eye 10.
FIGURE 4 illustrates an irrigation and
2S aspiration syringe 70 of the present invention. A
generally cylindrical syringe barrel 72 extends from
an opening 74 located at the rear of the barrel 72 to
a nozzle 76 located at the front of the syringe
barrel 72. The cortical cataractous material
aspirated from the eye is withdrawn into a chamber 78
of the syringe barrel 72 through the nozzle 76. A
first control grip 80 is positioned on the syringe
barrel 72 at a point proximate the nozzle opening
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76. The control grip 80 includes a forward sloping
surface 82 extending upwardly to join a rearward
sloping surface 84.
An outer sleeve 86 is dimensioned to slide over
the outer cylindrical surface of the syringe barrel
72. The sleeve 86 includes an open end 88 for
receiving the syringe barrel 72 and extends to a
closed end 90. A rod 92 is secured in the closed end
90 and extends to a plunger 94 dimensioned to closely
fit inside the hollow chamber 78 of the syringe
barrel 72. The outer sleeve member 86 has a second
control grip 96 extending from its outer surface at a
point proximate the open end 88. The control grip 96
includes a rearward sloping surface 98 extending from
the surface of the sleeve 86 to intersect a forward
sloping surface 100.
The nozzle 76 of the irrigation and aspiration
syringe 70 is connected to the needle 60. A balanced
intraocular irrigation solution is connected to the
inlet port 102 of the needle 60. The irrigation
solution flows through the needle 60 to a discharge
opening 104 to irrigate the eye during surgery. The
flow of the irrigation solution is regulated by
gravity pressure by adjusting the height of the
bottles containing the solution.
In operation, the needle 60 is inserted beneath
the cornea 18 in the manner shown in FIGURE 3.
Irrigation solution flows continuously into the
needle through the input port 102 through a discharge
port 104. The cortical cataractous material is
aspirated from beneath the cornea 18 by vacuuming the
material into the chamber 78 of the syringe 70
through the opening 66 of the needle 60. The syringe
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70 may be used to aspirate material from the eye by
single handed operation, leaving the surgeon's other
hand free to use a second instrument, if necessary.
The syringe 70 may be grasped with the thumb resting
on the forwardly inclined surface 82 of the first
control grip 80. The index finger rests against the
rearward sloping surface 98 of the second control
grip 96. Suction is applied by moving the outer
sleeve 86 in the direction indicated by the arrow
i~ 106, causing the plunger 94 to draw material up into
the chamber 78. The thumb applies a directive force
to the forward sloping surface 82 in the direction of
the axis of the syringe barrel 72 indicated by 108.
The index finger applies a force to the rearward
sloping surface 98 in the opposite direction along
the axis of the syringe barrel 72, as indicated by
the arrow 110. The suction pressure may be stopped
by reversing the movement of the outer sleeve 86, so
that the outer sleeve 86 moves forward in the
direction towards the nozzle 76 of the syringe. This
feature enables the surgeon to have precise one-
handed control to break the suction pressure if the
instrument engages the iris 28 or the posterior lens
capsule 31. The contents of the syringe 70 may be
emptied by drawing the needle 60 from the eye and
sliding the plunger 94 forward by moving the outer
sleeve 86 in the direction towards the nozzle 76 of
the syringe, opposite to that indicated by arrow
106. In discharging the contents from the syringe
70, the outer sleeve may be moved in the forward
direction by reversing the position of the thumb and
forefinger on the control grips 80 and 96, such that
the thumb is placed on the rearward inclined surface
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84 and the index finger rests on the forward inclined
surface 100.
FIGURE 5 illustrates an alternate embodiment of
the present invention, generally identified by the
reference numeral 7Q~. Many of the component parts
of the syringe 70' are substantially identical in
construction and function to component parts of the
syringe 70. Such identical component parts are
designate`d in FIGURE 5 with the same reference
1 numerals utilized hereinbelow in the description of
the syringe 70, but are differentiated therefrom by
means of a prime (') designation. In this
embodiment, the plunger 94' is connected through the
rod 92' to an outer sleeve 120 having a first
generally cylindrical section 122 dimensioned to fit
about the cartridge 72' and a second curved handle
section 124 to conform to the palm of the hand. The
* finger control grips 126, 128 and 130 are provided on
the side of the outer sleeve 120 opposite that of the
control grip 80' for the thumb. The control grips
126, 128 and 130 have generally rearward sloped first
surfaces 132, 134 and 136, respectively, and forward
sloped surfaces 138, 140 and 142, respectively. The
irrigation and aspiration syringe 70'imay be operated
in a similar manner to that described above for the
syringe 70. The outer sleeve 120 is retracted from
the cartridge 72 to draw the plunger in 94' and
provide suction to the opening 66'.
While the irrigation and aspiration syringe of
the present invention has been described in detail
herein, it will be evident that various and further
modifications are possible without departing from the
scope and spirit of the present invention.
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