U.S. patent application number 09/970850 was filed with the patent office on 2002-05-02 for removal of tissue.
This patent application is currently assigned to Aziz Yehia Anis. Invention is credited to Anis, Aziz Yehia, Steen, Mark Evan.
Application Number | 20020052617 09/970850 |
Document ID | / |
Family ID | 27090038 |
Filed Date | 2002-05-02 |
United States Patent
Application |
20020052617 |
Kind Code |
A1 |
Anis, Aziz Yehia ; et
al. |
May 2, 2002 |
Removal of tissue
Abstract
To reduce damage to surrounding tissue while fragmenting some
tissue such as for example not damaging the capsular wall while
removing the lens during cataract removal surgery or not damaging
artery or vein walls during bypass surgery while freeing the artery
or vein to be transplanted, an incision is made for the insertion
of a handpiece tip. The tip is rotated and reciprocated
ultrasonically at the same time so that tissue is fragmented by the
combined motion of a fragmenting surface perpendicular to the
surface and at an angle to the surface many times during a single
revolution or part of a revolution.
Inventors: |
Anis, Aziz Yehia; (Lincoln,
NE) ; Steen, Mark Evan; (Chino Hills, CA) |
Correspondence
Address: |
VINCENT L. CARNEY LAW OFFICE
P.O. BOX 80836
LINCOLN
NE
68501-0836
US
|
Assignee: |
Aziz Yehia Anis
Lincoln
NE
|
Family ID: |
27090038 |
Appl. No.: |
09/970850 |
Filed: |
October 4, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09970850 |
Oct 4, 2001 |
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09573288 |
May 18, 2000 |
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09573288 |
May 18, 2000 |
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09332709 |
Jun 14, 1999 |
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09332709 |
Jun 14, 1999 |
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08828928 |
Mar 28, 1997 |
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08828928 |
Mar 28, 1997 |
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08625909 |
Apr 1, 1996 |
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08625909 |
Apr 1, 1996 |
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08372866 |
Jan 13, 1995 |
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08372866 |
Jan 13, 1995 |
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08035985 |
Mar 22, 1993 |
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08035985 |
Mar 22, 1993 |
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07759937 |
Sep 16, 1991 |
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07759937 |
Sep 16, 1991 |
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07680292 |
Apr 4, 1991 |
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07680292 |
Apr 4, 1991 |
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07553975 |
Jul 17, 1990 |
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Current U.S.
Class: |
606/169 |
Current CPC
Class: |
A61B 2017/320077
20170801; A61B 2017/22008 20130101; A61B 17/22012 20130101; A61B
2017/22011 20130101; A61F 9/00763 20130101; A61F 9/00745 20130101;
A61B 17/320758 20130101; A61B 2017/32008 20130101 |
Class at
Publication: |
606/169 |
International
Class: |
A61B 017/32 |
Claims
What is claimed is:
1. Apparatus for removing tissue from a patient, comprising: means
for ultrasonically reciprocating a tip of a handpiece having a
longitudinal axis along said longitudinal axis wherein the tip is
symmetrical about its longitudinal axis and has an opening
extending along its longitudinal axis; means for rotating said tip
about said longitudinal axis in a first of clockwise and
counterclockwise direction; means for rotating said tip in a second
of clockwise and counterclockwise direction about its longitudinal
axis; means for changing directions repeatedly between said first
and second of clockwise and counterclockwise direction.
2. Apparatus in accordance with claim 1 in which the means for
ultrasonically reciprocating the tip of the hand piece is a
piezoelectric crystal.
3. Apparatus in accordance with claim 1 in which the means for
ultrasonically reciprocating the tip of the handpiece is an
electromagnetic vibrator.
4. Apparatus in accordance with claim 1 in which the means for
rotating the tip of the handpiece is an electrical motor.
5. Apparatus for removing tissue from a patient in accordance with
claim 1 further comprising means for aspirating particles through
the tip of the handpiece.
6. Apparatus in accordance with claim 5 in which the means for
aspirating particles is an opening and a vacuum pressure means.
7. Apparatus for removing tissue from a patient in accordance with
claim 1 comprising means for aspirating vitreous fluids through the
tip of the handpiece.
8. Apparatus for removing tissue from a patient comprising means
for reciprocating a tip of a handpiece ultrasonically and rotating
the tip of the handpiece in more than one direction.
9. Apparatus in accordance with claim 8 in which the means for
reciprocating the tip of the handpiece ultrasonically is an
ultrasonic vibrator and the means for rotating the tip of the
handpiece is an electrical rotational motor.
10. Apparatus for removing tissue from a patient comprising means
by which a power source that energizes a handpiece may drive any of
a plurality of handpieces or instruments.
11. Apparatus in accordance with claim 10 in which the means for
driving any of a plurality of handpieces or instruments is an
interface which includes a handpiece simulator connected to a
console that matches an output impedance of the console to an input
impedance of the handpiece.
12. A method of removing tissue from a patient comprising the step
of driving a cutting tip with an electrical rotational motor; said
step of driving comprising applying a pulse having a first polarity
to the electrical rotational motor to cause the tip to turn in a
first direction and applying a pulse having a second polarity to
the electrical rotational motor to turn the tip in a second
direction.
13. Apparatus for removing tissue from a patient comprising: a
cuffing tip; an electrical rotational motor connected to the
cutting tip to rotate the cutting tip; and a pulse circuit for
applying pulses of different polarities to the rotational
motor.
14. A method according to claim 12 further including the step of
ultrasonically reciprocating the cutting tip with an ultrasonic
vibrator.
15. A method according to claim 12 further including the step of
alternating between the step of applying a pulse having a first
polarity to the electrical rotational motor and applying a pulse
having a second polarity to the electrical rotational motor so that
the cutting tip turns in the first direction, then in the second
direction repeatedly.
16. A method according to claim 12 wherein the cutting tip is
driven by a power source which may drive any of a plurality of
handpieces or instruments.
17. Apparatus in accordance with claim 13 further comprising a
piezoelectric crystal connected to the cutting tip to
ultrasonically reciprocate the cutting tip.
18. Apparatus in accordance with claim 13 further comprising an
electromagnetic vibrator connected to the cutting tip to
ultrasonically reciprocate the cutting tip.
19. Apparatus in accordance with claim 13 further comprising means
for aspirating particles and vitreous fluids through the cutting
tip.
Description
RELATED CASE
[0001] This application is a divisional of U.S. application Ser.
No. 09/573,288 filed May 18, 2000, which is a divisional of U.S.
application Ser. No. 09/332,709 filed Jun 14, 1999, now U.S. Pat.
No. 6,203,518, which is a divisional of U.S. application Ser. No.
08/828,928 filed Mar. 28, 1997, now U.S. Pat. No. 5,911,699, which
is a continuation-in-part of U.S. application Ser. No. 08/625,909
filed Apr. 1, 1996, now U.S. Pat. 5,722,945, which is a
continuation-in-part of U.S. application Ser. No. 08/372,866 filed
Jan. 13, 1995, now abandoned, which is a continuation of U.S.
application Ser. No. 08/035,985 filed Mar. 22, 1993, now abandoned,
which is a continuation-in-part of U.S. application Ser. No.
07/759,937 filed Sep. 16, 1991, now abandoned, which is a
continuation of U.S. application Ser. No. 07/680,292 filed Apr. 4,
1991, now abandoned, which is a continuation-in-part of U.S.
application Ser. No. 07/553,975 filed in the name of Aziz Y. Anis
on Jul. 17, 1990, now U.S. Pat. No. 5,222,959 for REMOVAL OF
TISSUE.
BACKGROUND OF THE INVENTION
[0002] This invention relates to the removal of tissue from the
body such as for example removal of cataracts from the eye.
[0003] It is known to remove diseased tissue from the body by
fragmenting, crushing or otherwise making the tissue flowable while
in the body and then aspirating it. In one known class of surgical
techniques of this type specifically intended for the removal of
cataracts: (1) an incision is made along the superior corneal
margin from about 10 to 2 o'clock (12 o'clock is the location
closest to the top of the head of the patient) approximately 10 mm
in chord length; (2) an incision is made in the capsular wall; and
(3) the cataract is removed. The anterior chamber is maintained
substantially formed during the operation by means of a continuous
inflow of irrigating solution.
[0004] In one prior art technique of this class for removing a
cataract, the nucleus is expressed out of the eye and the cortex is
removed by a process of irrigation and aspiration. In another prior
art technique of this class for removing the cataract, the nucleus
is removed with a vectis and about 0.1 milliliter of viscoelastic
compound or irrigating fluid is introduced into the capsular bag to
separate the capsular walls. With the capsular walls separated, a
wedge of the cortex is engaged in the aspiration port of a cannula
and peeled toward the center and then aspirated to remove it. This
process is repeated so that the layers of the cortex are peeled and
then aspirated inwardly through the cannula, layer by layer, until
the intact capsular bag (except for the horizontal incision) is
completely empty and clean.
[0005] This technique of removing the cataract is disclosed by
Anis, Aziz Y., "Illustrated Step-by-Step Description of the Anis
Dry Extra Capsular Cataract Extraction Technique With In-the-Bag
Lens Implementation"; Seminars in Ophthalmology, v. 1, N. 2 (June),
1986, pp. 113-129 and the technique is compared with other such
techniques of this class.
[0006] Two prior art types of instruments which aid in the
fragmentation and aspiration of the lens nucleus to permit
extraction through a small incision are disclosed in U.S. Pat. No.
3,589,363 to Anton Banko et al.; U.S. Pat. No. 3,902,495 to Steven
N. Weiss; U.S. Pat. No. 3,693,613 to Charles Kelman et al.; and
U.S. Pat. No. 4,041,947 to Steven N. Weiss et al. This instrument
is intended in the prior art to fragment a lens nucleus using
ultrasonic vibrations to aid the irrigation/aspiration of the lens.
The ultrasonic vibrations laterally reciprocate the tip of an
instrument to fracture the cataract after which it can be
aspirated.
[0007] A further type of instrument is disclosed in U.S. Pat. No.
4,908,015 issued to Anis on Mar. 13, 1990. This patent describes an
instrument which rotates a solid member having blades extending
from it to grind the lens.
[0008] These tissue removal techniques have several disadvantages,
such as: (1) they risk tearing the capsular wall with the
reciprocating ultrasonic vibration tools or with the rotating
blades; (2) under some circumstances, they require large incisions
in or removal of parts of the capsular wall; and (3) they may
require the use of several different instruments.
[0009] Still another type of prior art technique for removing
cataracts is disclosed in U.S. Pat. No. 3,996,935 to Banko issued
Dec. 14, 1976. This type of instrument shows cooperating jaw-like
members, one of which rotates inside the other to break up the lens
by shearing sections of it. It aspirates fragments through the
instrument. This type of instrument has a disadvantage in that it
can break the capsular wall and is relatively complex. Part of the
disadvantage comes from the teaching that it may be rotated
manually or mechanically without a corresponding teaching of the
rate of rotation required for efficient use.
[0010] Still another prior art instrument includes a small rotary
magnetic cutter that is injected through the capsular wall and a
means for applying magnetic fields that control the magnetic cutter
in position. The small magnetic cutter is rotated as it moves from
position to position in the capsular bag and to abrade or cut the
lens that is to be removed.
[0011] This instrument has several disadvantages, such as: (1) it
is relatively complicated and expensive because of the need to
remotely control the small cutter; and (2) does not incorporate any
mechanism for aspirating the lens particles as they are abraded
from the lens.
[0012] In still another prior art device disclosed in U.S. Pat. No.
4,002,169, small retractable wires are rotated in a range of 5 rpm
to 16,000 rpm. There is no teaching of selecting the speed for
surface discrimination and the device relies on blunt surfaces to
avoid damage to the capsular wall instead. This device has the
disadvantages of: (1) providing a relatively slow cutting velocity
range with blades not shaped for cavitation or turbulence; (2) not
providing a range of velocities sufficient to form small particles
that can be aspirated through a small hole; and (3) not providing
for aspiration during fragmenting, thus blocking visibility with
particles.
[0013] Each of these prior art types of instruments includes a
handpiece and a console. The handpiece is held by the surgeon and
includes an operative tip that, at one point in time, enters the
capsular sac to fragment and remove the cataract. The console
includes controls for the handpiece such as those that control the
direction of movement and speed of movement of the tip, rate of
flow of liquids, the suction or aspiration pressure and the drivers
that apply power to the hand-piece at the appropriate values.
Generally, the consoles are designed together with a particular
type of hand-piece used in a specialized technique of ocular
surgery.
[0014] A still further type of instrument is disclosed in U.S. Pat.
No. 4,504,264 to Kelman issued Mar. 12, 1985. This patent discloses
an instrument that reciprocates a cutting tip ultrasonically and
oscillates it rotationally about its longitudinal axis at a rate of
one hertz through an angle of between five degrees to 60 degrees.
Because of dwell time at each change of rotational direction and
speed limitations inherent in the direction changes, this
instrument does not provide the advantage of breaking the tissue
into particles so small as to not cause plugging nor impede
visibility of the instrument tip.
[0015] The prior art arrangement has several disadvantages, such as
for example: (1) it is difficult for the surgeon to use the most
modern techniques without investing substantial amounts of money in
purchasing additional consoles for the newer instruments; (2) for
each new handpiece designed for a particular technique, the surgeon
must adapt to different controls in the console itself rather than
relying upon controls with which he is already familiar; (3) the
handpieces are subject to causing plugging, poor visibility into
the eye and excessive pressure on the capsular wall from movement
of large particles; and (4) different equipment is necessary to
remove vitreous liquids.
SUMMARY OF THE INVENTION
[0016] Accordingly, it is an object of the invention to provide a
novel technique for tissue removal.
[0017] It is a further object of the invention to provide a novel
instrument for fragmenting and removing a cataract during cataract
removal surgery with low risk of damage to the capsular wall.
[0018] It is a still further object of the invention to provide a
novel instrument designed to fragment tissue without damage to the
nearby tissue such as for example not damaging the capsular wall
while removing the lens during cataract removal surgery or not
damaging artery or vein walls while removing cancerous tissue near
the vein or artery.
[0019] It is a still further object of the invention to provide a
novel instrument and method for removing tissue that powders the
tissue and aspirates it while maintaining good visibility.
[0020] It is a still further object of the invention to provide a
novel interface that permits the connection of a phacotmesis
handpiece to consoles designed specifically for other ocular
surgery such as consoles designed originally to cooperate with a
phacoemulsification handpiece.
[0021] It is a still further object of the invention to provide an
instrument capable of vitrectomy and removal of cataracts with the
same handpiece.
[0022] In accordance with the above and further objects of the
invention, an incision is made for the insertion of a
surface-discriminating, fragmenting tool. The
surface-discriminating, fragmenting tool fragments and permits
aspiration of high mass, rough-surface, rigid tissue without
damaging nearby smooth, flexible, low mass walls. The tool
fragments some tissue but avoids fragmenting other tissue by
discriminating between tissues. This discrimination is based on one
or more of several factors including: (1) the rigidity of the
tissue; (2) the amount of mass of the tissue; (3) the angle of the
tissue to the direction of movement of the tool; (4) the roughness
of the surface of the tissue; and (5) the size and shape of the
surface of the tissue to the extent the size and shape affect the
tendency of the negative pressure created by aspiration and/or
irrigation to move the tissue toward the surface-discriminating,
fragmenting tool.
[0023] The surface discrimination of the tool is controlled by
moving surfaces which fragment diseased tissue on impact, referred
to as phacotmesis, and cause cavitation forces that further
fragment and mix fragments of tissue, referred to as phacocoelosis,
but which move at a rate of speed slow enough so that the more
integrated, more flexible, lower mass and smoother tissue is moved
away without fragmenting. The tissue is not constrained by opposed
shear forces of the tool as in some prior art rotating tools nor is
the higher mass, rigid tissue moved significantly as a bulk.
[0024] The surfaces of the instrument fragment tissue that: (1) is
stiffer and has a higher modulus of rigidity; and (2) is at an
angle to the cutting edge closer to 90 degrees and receives less
force moving it away. Thus, the surgeon removing a cataract adjusts
the speed of movement of the tool surfaces, the aspirating and
irrigation forces, the rake angle of the tip and the cavitation
level as controlled by the position of the tool surface, the
velocity and the shape of the moving surface. The adjustment is
made to fragment the cortex because of its higher mass, modulus of
elasticity and projections in the path of the tool surfaces but to
move the capsular wall because of its lower mass, lower modulus and
fewer projections closer to 90 degrees and not fragment it.
[0025] In one embodiment, a moving, fragmenting surface moves at an
angle with the normal to a cataract surface, which angle is obtuse
and generally close to being perpendicular to the normal in such a
manner as to mix particles and to cause or aid ultrasonic motion
normal to the tissue in causing cavitation and in fragmenting and
mixing the cataract particles while maintaining the direct force on
the cataract that could accelerate tissue against the capsular wall
relatively low. In a preferred embodiment, the fragmenting surface
is moved ultrasonically along the normal while it is moving at an
angle to the normal such as by rotating continuously at least
through several 360 degree rotations in one direction.
[0026] The aspiration pressure is more effective within the moving
surfaces of the rotating tip. It is low enough to pull the
fragmented tissue and tissue to be fragmented but it does not hold
the smooth flexible capsular wall against movement away from the
moving surfaces of the tool. The rotating surfaces move the smooth
wall outwardly and provide some counter pressure to the aspirating
pressure inside the fragmenting zone. The vibrating speed and
rotational speed can be adjusted to powder the cataract so as to
maintain good visibility and ease of aspiration and can be adjusted
for vitrectomy.
[0027] In the case of cataract removal surgery, a small incision of
two to seven millimeters and preferably three millimeters is made
in the sclera along the corneal border at 12 o'clock and another
incision of similar dimension or a round hole is made in the
anterior capsular wall. The instrument is inserted and fragments
the lens matter without fragmenting the capsular wall. The factors
useful in surface-discriminatory, fragmenting differ from eye to
eye or tissue to tissue and may be selected in accordance with the
surgeon's observations. These factors are the speed of the moving
surfaces with respect to the tissue, the holding pressure from
aspirating vacuum and irrigating liquid, the location and position
of the moving surfaces, the rake angle of the cutting edge of the
moving surfaces and the shape of the portions of the moving
surfaces most related to cavitation. These factors are established
by the surgeon as a function of the mass of the capsular wall and
the mass of the tissue to be fragmented, the stiffness and
smoothness of the capsular wall or other healthy smooth tissue and
the hardness and flexibility of the tissue.
[0028] In one embodiment, moving surfaces of the fragmenting tool
hit the cells at a substantially tangential angle and distort them
or cut them with their leading edges while the trailing edges
create cavitation that further breaks and mixes the tissue without
imparting such force to the tissue in a direction that may injure
the capsular wall. For large and rigid or for rough surfaces, the
shear force and cavitation is sufficient for fragmentation whereas
for more flexible, lower mass and smoother surfaces, the leading
edges and the cavitation tend to move the surface away and thus
avoid fragmentation. The aspirating port or ports tend to pull the
fragmented material into the interior of the tool.
[0029] In a preferred embodiment, a tubular member has a central,
aspirating channel along its longitudinal axis with one end having
a fragmenting tip and the other end being adapted to rotate the
tube. In one embodiment, the cavitation is at low frequency below
the ultrasonic frequency range. In a preferred embodiment, the tip
is rotated continuously in one direction for more than one 360
degree cycle and at the same time ultrasonically reciprocated.
[0030] As can be understood from the above description, the
technique and instrument of this invention have several advantages,
such as: (1) they selectively fragment some tissue without damaging
other nearby tissue; (2) they are able to fragment, mix and
aspirate tissue, and in the case of cataract removal, while
maintaining good visibility; and (3) the same handpiece can perform
vitrectomy.
SUMMARY OF THE DRAWINGS
[0031] The above noted and other features of the invention will be
better understood from the following detailed description when
considered with reference to the accompanying drawings, in
which:
[0032] FIG. 1 is a simplified, elevational view of a handpiece and
control console for fragmenting and removing cataracts in
accordance with an embodiment of the invention;
[0033] FIG. 2 is an enlarged, perspective view of a portion of the
embodiment of FIG. 1;
[0034] FIG. 3 is a fragmentary, sectional view of another portion
of the embodiment of FIG. 1;
[0035] FIG. 4 is a fragmentary, perspective view of another
embodiment of blade portion usable as a replacement for the blade
portion in the embodiment of FIG. 1;
[0036] FIG. 5 is a plan view of the embodiment of FIG. 4;
[0037] FIG. 6 is a fragmentary, elevational view, partly sectioned
and partly diagramatic of another embodiment of handpiece;
[0038] FIG. 7 is a fragmentary, elevational view of another
embodiment of tool portion;
[0039] FIG. 8 is a top view of the embodiment of FIG. 7;
[0040] FIG. 9 is an elevational, right hand view of the embodiment
of FIG. 7;
[0041] FIG. 10 is a fragmentary, elevational view of a tool tip
which represents a variation of the tool tip of FIGS. 7-9;
[0042] FIG. 11 is a diagramatic, top view of a tool tip
illustrating a first step useful in making the embodiment of FIGS.
7-9;
[0043] FIG. 12 is a fragmentary, elevational view of the tool tip
shown in FIG. 11;
[0044] FIG. 13 is an elevational view of a tool tip illustrating a
second step in preparing the embodiment of FIGS. 7-9;
[0045] FIG. 14 is a top view of the tool tip shown in FIG. 13;
[0046] FIG. 15 is a fragmentary, perspective view illustrating an
additional step in preparing the embodiment of FIGS. 7-9;
[0047] FIG. 16 is a perspective view illustrating still another
possible step in preparing a tool tip similar to the embodiments of
FIGS. 7-9;
[0048] FIG. 17 is a block diagram of a process for using the
instrument of FIGS. 1-6 to remove a cataract;
[0049] FIG. 18 is a simplified, cross-sectional view of an eye and
cataract removal handpiece tip illustrating a portion of the
technique of this invention;
[0050] FIG. 19 is a fragmentary, elevational view, partly sectioned
and partly diagramatic of still another embodiment of
handpiece;
[0051] FIG. 20 is a sectional view of another embodiment of
handpiece;
[0052] FIG. 21 is a sectional view of a tip usable in the
embodiment of FIG. 20;
[0053] FIG. 22 is a block diagram of a console interface for
connecting any of several different consoles to a phacotmesis
handpiece and a phacotmesis handpiece;
[0054] FIG. 23 is a schematic circuit diagram of an interface
circuit; and
[0055] FIG. 24 is a block diagram of an ultrasonic driver
circuit.
DETAILED DESCRIPTION
[0056] In FIG. 1, there is shown an elevational view of a
surface-discriminating, fragmenting handpiece 10, connecting tubing
23 and a console 21. The handpiece 10 includes a drive portion 11,
a blade portion 14 and a tubular sleeve portion 12. The tubular
sleeve portion 12 includes a tubular casing 13 and an inner tubular
aspirating drive shaft or sleeve 18. The drive portion 11 houses
the motor, an on-off switch 20 and connectors for irrigating fluid
and aspirating vacuum pressure.
[0057] The blade portion 14 includes blades 17A and 17B each of
which is fastened to the rotatable tubular shaft 18 at
diametrically opposite locations on the shaft 18 and each of which
has a corresponding one of blunt tips 15A and 15B turned inwardly
to avoid cutting. The outer tubular casing 13 includes within it a
movable sleeve 19A so that upon longitudinal movement of a button
19 with respect to the outer casing 13 of the tubular sleeve
portion 12, the blades 17A and 17B move apart in a fragmenting
position in response to one direction of movement of the button 19
and are forced within the movable sleeve 19A within the tubular
sleeve portion 12 against the pressure of the spring-like blades
17A and 17B upon movement in the other direction of the button 19
to fit within a smaller incision such as a 2 millimeter opening.
The blades 17A and 17B are narrower in the direction of rotation
and blunt on the trailing edge to cause cavitation.
[0058] With this arrangement, the blades 17A and 17B may be moved
together for insertion of the handpiece 10 into a capsular sac
through a relatively small aperture and then permitted to expand
outwardly so that upon rotation of the blade portion 14, the cortex
and nucleus are fragmented within the capsular sac. In the
embodiment of FIG. 1, the handpiece 10 includes a motor for
rotating the shaft and a connecting tubing 23 for aspirating
fragments. The console 21 may include for cooperation with the
handpiece 10, a standard source of electrical power, a vacuum
source, a source of irrigating liquid and a pump for irrigating
liquid. These elements are conventional and are not part of the
invention except insofar as they cooperate with the handpiece
10.
[0059] In FIG. 2, there is shown an enlarged, fragmentary
perspective view of the blade portion 14 of the tool assembly
having first and second blades 17A and 17B with corresponding blunt
ends 15A and 15B. The blades 17A and 17B are sufficiently flexible
in the embodiment of FIG. 2 to expand until they form outwardly,
curved, cutting surfaces extending beyond the surfaces of the outer
casing or shaft 13 (FIG. 1) and have sharpened edges 32 and 34
tangentially to or pointing inwardly from the circles of rotation
formed as they rotate. When the blades 17A and 17B are pulled
inwardly by movement of the sleeve 19A upwardly, they fit within a
cylinder having a diameter of less than two millimeters.
[0060] While the embodiment of FIGS. 1 and 2 have blades with
sharpened edges pointing tangentially to or inwardly from the
direction of rotation, sharpened edges are not necessary and the
angle of attack or rake angle of the sharpened edges may vary.
However, the angle of attack may be tangential to the path of
rotation or any larger or smaller angle. For this purpose, any one
of several multiple blade portions 14 with their attached inner
drive shaft 18 may be inserted into the sleeve portion 12 and drive
portion 11. The blade portion is selected by the physician and one
fact in such selection is the angle of attack of the blades.
[0061] To permit compressing of the blades 17A and 17B into a
protective sleeve, the tubular sleeve portion 12 includes the three
coaxial sleeves 18, 19A and 13 (FIG. 1) in that order outwardly
from the central axis. The blades 17A and 17B are mounted to the
inner tubular drive sleeve 18 for rotation therewith and there is a
space between the sleeves 18 and 19A for irrigating fluid to flow.
The movable sleeve 19A is affixed to the button 19 (FIG. 1) and is
movable axially with respect to inner drive sleeve 13 to engage the
blades 17A and 17B and to compress them inwardly.
[0062] In FIG. 3, there is shown a fragmentary longitudinal
sectional view of the tubular sleeve portion 12 and the drive
portion 11: (1) having within the sleeve portion 12, the inner
rotatable tubular aspirating drive shaft or sleeve 18, the movable
tubular protective sleeve 19A and the outer sleeve 13; and (2)
having within the drive portion 11, a motor 40 for rotating the
inner aspirating drive shaft 18 to turn the blades 17A and 17B
(FIG. 1), a hollow aspirating tube 27 to apply vacuum pressure to
the interior of the inner shaft 18, an irrigating tube 17
communicating with the movable sleeve 19A to apply irrigating fluid
through the sleeve 19A and through electrical wires 25 to control
the motor 40. The inner shaft 18 is coupled at one end 42 to the
output shaft 44 of the motor 40 for rotation therewith and to a
tubular connection 45 for aspiration.
[0063] As shown in this view, the outer sleeve 13 supports within
it the movable sleeve 19A with the button 19 extending through a
slot in the outer sleeve 13 by which the movable sleeve 19A may be
moved upwardly and downwardly to bend the blades 17A and 17B
inwardly for retraction or to permit them to expand outwardly in
the cutting position to their normal position for rotating and in
some embodiments still further under centrifugal force when
rotating. However, the moment of inertia of the blades 17A and 17B
is sufficient so that the centrifugal force does not force the
points to point outwardly and only the bent flat surface is
presented to the outer sleeve 13 during rotation. It is spaced from
the movable tube 19A to permit irrigating fluid to flow there
between and contains in its center, an opening 15 which extends
downwardly for aspiration of tissues.
[0064] To provide irrigating fluids, the irrigating tube 17 is
connected through a cable 23 to the console 21 (FIG. 1) from which
irrigating liquid is pumped through the tube 17 around the motor 40
and to the space between the movable tube 19A and the inner shaft
18 to supply irrigating fluid to the capsular sac. To aspirate
tissue, the central opening 15 in the inner shaft 18 passes through
an opening 29 in the wall of the inner shaft 18 and communicates
through a sealed circular ring 31 with the aspirating conduit 25.
The connection 45 passes around the motor 40 and through the cable
23 to the console 21 (FIG. 1) which applies slight negative
pressure to aspirate tissue. The cable 23 also carries electrical
conductors for the motor 40 which are connected in series between
the switch 20, and a source of electrical power in the console 21
and the motor 40.
[0065] To use the embodiment of FIGS. 1-3, an incision is made for
the insertion of the surface-discriminating, fragmenting handpiece
10. The surface-discriminating, fragmenting handpiece 10 fragments
and permits aspiration of the tissue but avoids damaging nearby
smooth, flexible walls. Instead, it fragments rougher, more rigid
surfaces of higher masses. This surface discrimination is
controlled by the moving surface of the blades 17A and 17B, which
permit the diseased tissue to be strained or cut by the blades 17A
and 17B and further fragmented by the forces of cavitation within
their fragmenting zone but which move at a rate of speed and have
openings between them of such a size that the more integrated,
lower mass or more flexible and smoother tissue does not fall
within their fragmenting zone but is moved away from the moving
surfaces. The aspirating pressure, cavitation and turbulence is
counteracted or attenuated within the sphere of the rotating ring
to avoid damage to the flat surface tissue.
[0066] In the case of cataract removal surgery, a small incision of
two to seven millimeters and preferably three millimeters is made
in the sclera along the corneal border at 12 o'clock and another
incision of similar dimensions is made in the capsular wall. The
instrument is inserted and fragments the higher mass, more rigid,
rougher lens without fragmenting the capsular wall.
[0067] The actual time that the fragmenting zone must be open to
fragment diseased tissue without injuring smooth walls differs from
eye to eye or tissue to tissue and may be selected in accordance
with the surgeon's observations prior to use. It is a function of:
(1) the rigidity of the tissue; (2) the mass of the tissue; (3) the
angle of the tissue to the direction of movement of the tool; (4)
the roughness of the surface; and (5) the effect of the negative
pressure pulling the tissue inwardly such as the aspiration vacuum
pressure which may vary in its effect depending on the size and
shape of the tissue.
[0068] The surface discrimination of the tool is controlled by
moving surfaces which cause the diseased tissue to fragment under
impact, referred to as phacotmesis, and cavitation forces, referred
to as phacocoelosis, but which move at a rate of speed slow enough
so that the more integrated, more flexible, lower mass and smoother
tissue is moved away without fragmenting. The surfaces of the
instrument fragment tissue that: (1) is stiff; (2) has a high mass
and large inertia; and (3) is at an angle to the cutting edge close
to 90 degrees.
[0069] To take advantage of the differences between the tissue to
be fragmented and the lower, more flexible tissue, the surgeon
removing a cataract adjusts the speed of movement of the tool
surfaces, the aspirating and irrigation rates, the rake angle of
the leading edge of the blade surfaces and the cavitation level as
controlled by the position of the blade surfaces, the velocity and
the shape of the moving surfaces, especially the trailing edge of
the blades. The adjustments are made to fragment the cortex because
of its higher mass, modulus of elasticity and projections in the
path of the tool surfaces and to move the capsular wall away from
the blades because of its lower mass, lower modulus and fewer
projections closer to 90 degrees. Tips are replaced to change the
rake angle and cavitation surfaces.
[0070] The aspiration pressure is more effective within the moving
surfaces of the rotating tip. It is low enough to pull the
fragmented tissue and tissue to be fragmented but does not hold the
smooth wall against movement nor pull it inwardly. The rotating
surfaces move the smooth wall outwardly and provide some counter
pressure to the aspirating pressure inside the fragmenting zone. In
one embodiment, radially, inwardly, extending edges further pull
and mix tissue within the fragmenting zone.
[0071] To better describe this and other embodiments, some special
terminology is useful. For purposes of this description, the words,
"low power" mean less than one horsepower (1.341 kilowatts). In
this description, the words, "motion resistance" mean the
resistance of a portion of tissue to movement when impacted by a
moving tool surface caused by the inertia of the tissue and the
effect of the inertia of other tissue connected to it taking into
consideration the flexibility of the connecting tissue.
[0072] In this description, the words, "fragmenting velocity" mean
the minimum velocity of a moving surface of a tool with respect to
predetermined stationary tissue that the moving surface of the tool
impacts that is sufficient to cause strain in the tissue of at
least ten percent of the distance moved by the entire tissue mass
and to break the tissue by combined strain, cutting and cavitation
effects. This value is specific for a predetermined stationary
tissue having a predetermined motion resistance. It assumes that
the tool surface has sufficient kinetic energy to maintain its
velocity constant in spite of the impact. The fragmenting velocity
is affected by: (1) the angle the motion of the moving surface
makes with the surface of the tissue; and (2) the momentum of the
moving surface.
[0073] In the embodiments of FIGS. 1-3, a ring or partial ring
having a diameter of two millimeters in the widest distance
perpendicular to the axis of revolution forms a surface of
revolution when rotated having at any one time open spaces and a
solid cutting ring. The ring is rotated at approximately 120,000
rpm (revolutions per minute). The solid ring is approximately 0.50
millimeter wide along the surface of revolution, leaving an open
area in the surface of slightly less than nine square millimeters
and more precisely, 8.9 square millimeters with a length of 2.4
millimeters at the longest circle of a segment.
[0074] The time between portions of the solid ring sweeping across
any surface of revolution is approximately every 250 microseconds
and should be no longer than once every three milliseconds (1,000
rpm) but may be as short as 0.75 of a microsecond (400,000 rpm).
With this arrangement and with parameters adjustable for the
particular circumstance, the capsular wall does not enter into the
fragmenting zone within and near the surface of revolution and is
not cut and yet the ring is able to fragment the lens for easy
aspiration.
[0075] In FIG. 4, there is shown a second embodiment of blade
portion 14A, having a shaft 18A connected to a blade 17C formed as
a partial zone of a circle or an arc extending from the shaft 18A
and having a pear-shaped, blade portion 14A with: (1) blunt
trailing edges 20; (2) sharpened leading edges 22; (3) a wide base
attached to the shaft 18A that is narrower along the axis of the
shaft 18A so that there is at the wide portion, a blunt trailing
edge 20 and a sharpened leading edge 22 as the cutting blade 17C
rotates about the shaft 18A; and (4) an axis of rotation along the
shaft 18A between the base and the narrower upper portion. The apex
is generally blunt, but in some embodiments has a drill shape at
the apex 24.
[0076] It has been found that the sharpened leading edges 22 strain
and elongate the cells of higher-mass, rigid material but push away
flexible and low-mass material. The leading edges 22, under some
circumstances, cut or scrape fine particles from the harder
material that might otherwise plug the aspirating channel but the
cavitation effect fragments the particles into small particles that
can easily be aspirated. The blades 17C are shaped to maximize
cavitation that liquifies and stresses lens matter and any viscous
fluids and causes fragmentation and mixing of the higher-mass more
rigid material. In the embodiment of FIG. 4, the blades have two
blunt sides, a top blunt portion 24 and a blunt portion at the
mounting base to the tube 18A for strength at the bottom and to
form a non cutting surface at the top.
[0077] In FIG. 5, there is shown a top view of the embodiment of
FIG. 4, having the blade portion 14A with the blade 17C shaped with
a thicker portion having a blunting surface 24 at its upper end
facing away from the direction of the tubular shaft 18A and
rotating thereabout. However, in some embodiments, it has a cutting
edge to permit it to provide an abrading center area in the forward
direction for positioning at a point to be fragmented. This
embodiment operates substantially the same as the prior embodiments
except that its unique shape enables careful placement for special
purposes. Instead of a cutting edge, the top portion 24 may be bent
inwardly or may be blunt to avoid cutting at its top.
[0078] In FIG. 6, there is shown a fragmentary, partly diagramatic
and partly longitudinally sectioned view of another embodiment of
handpiece 10A which is operated by a similar dental drill motor 40
and adapted to receive a tool by having inserted therein an
aspirating drive sleeve 18B of a tubular sleeve portion 12C
substantially identical to that of the embodiments of FIGS. 1-5
except that the blade portion is constructed in a different manner
on the end of the inner shaft 18 (FIG. 1-3) as will be described
hereinafter.
[0079] The handpiece 10A includes, in addition to the
aforementioned motor 40 and the aspirating drive sleeve 18B, an
outer housing 60 and a motor-tool sleeve coupling 62 with: (1) the
motor 40 being connected to the drive sleeve 18B through the
coupling 62 and being located within the outer housing 60; (2) the
sleeve 18B extending outwardly thereof for rotation by the motor 40
through the coupling 62 during operation of the handpiece.
[0080] To enclose and provide the necessary liquid and vacuum
connections to the operative tool, the outer housing 60 includes a
motor housing portion 70 and a tool and coupling housing portion 72
integrally formed together with a tubular connector 74 for
irrigating fluid, a tubular connector 76 for aspirating negative
pressure and a hole 78 being provided through the housing 60 for
venting air. The air vent port 78 is an opening extending into and
communicating with the interior of the motor housing portion 70 to
provide cooling to the motor 40. The irrigating fluid connector 74
is an opening communicating with the interior of the housing
portion 72 to apply fluid therethrough for eventual passage through
a protective sleeve 13A on the outside of the drive sleeve 18B and
to the operating point in a manner to be described more fully
hereinafter.
[0081] The aspirating connector 76 is adapted to receive tubing for
applying negative pressure through the motor-tool sleeve coupling
62 to the interior of the drive sleeve 18B to withdraw material
during use of the handpiece 10A. The forward end of the tool and
coupling housing portion 72 includes external threads 82 which
engage internal teeth 112 on the protective sleeve 13A and a
shoulder with an O-ring 80 positioned in it so that the protective
sleeve 13A can be threaded onto the outer housing 60 to enclose a
portion of it sealingly and extend it through its outer end in a
manner to be described hereinafter.
[0082] To connect the motor 40 to the sleeve portion 12C, the
motor-tool sleeve coupling 62 includes a motor output shaft 90, a
cylindrical boss 92, a cylindrical support member 94, an annular
groove 96 within the support member 94, two counterbores 98 through
the support member 94 at the bottom of the annular groove 96, an
opening 100 communicating with the aspirating connector 76 and
extending through the cylindrical support member 94, a cylindrical
opening 95 sized to receive the sleeve 18B and a brazed connection
102 more firmly fastening the support member 94 to the sleeve 18B.
A support 101 receives the motor shaft 90 and the boss 92 which
rotate within it and are supported by it. The groove 96
communicates with the opening 100 as it rotates because of its
annular shape and receives vacuum pressure which it transmits
through the counterbores 98 into the sleeve 18B to create negative
pressure in the working tip through this elongated sleeve.
[0083] With this arrangement, the sleeve 18B is rotated and carries
vacuum pressure with it to the tip. The brazed connection 102 aids
in transmitting force from the output shaft 90 to the drive sleeve
18B through the boss 92 by increasing the firmness of the
connection between the drive sleeve 18B and the shaft 90.
[0084] To mount and support the drive sleeve 18B, the protective
sleeve 13A in the embodiment of FIG. 6 includes a cylindrical base
member 110 having internal teeth 112 adapted to engage the external
teeth 82 of the housing portion 72 and is sealed against the flow
of fluid therethrough by the O-rings 80 compressed between the
enlarged cylinder base member 110 and the housing portion 72. A
narrower outer sheath portion 114 is integrally formed with the
cylindrical base member 110 and receives a cylindrical passageway
formed between the inner drive sleeve 18B and its outer tubular
surface to permit the flow of irrigating liquid between the outer
protective sleeve 13A and the inner drive sleeve 18B into the
capsular bag.
[0085] With this arrangement, the drive sleeve 18B can be rotated
by the motor 40 and at the same time: (1) irrigating fluid can be
applied between it and the protective outer sleeve 13A; and (2)
aspirating negative pressure can be applied to pull fragments along
its longitudinal axis. At its outer end, the fragmenting tip or
blades are formed in a manner to be described hereinafter.
[0086] In FIG. 7, there is shown a front, elevational view of one
embodiment of a tool having a sleeve portion 12A and a blade
portion 14B with two blade members formed in its outer end and
separated by an opening 123 longitudinally passing along the
longitudinal axis of the tool to form the blade portion 14B at the
end of the same cylinder forming the sleeve portion 12A. Both the
blade portion 14A and the sleeve portion 12A are formed on a
single, integrally formed cylinder that serves as an aspirating
drive shaft 18B. Aspirating holes extend through the tip of the
blade portion 14B orthogonal to the longitudinal axis and a slot
120 (FIGS. 8 and 9). To receive some material for aspirating,
apertures 122 and 123 (FIGS. 8-10) are approximately 0.04 inch from
the tip 24 (FIG. 10) of the blade portion 14B and the diameter of
the aspirating drive shaft 18B is a approximately 0.042 inch. The
diameter of the aspirating apertures 122 and 123 are 0.018 inch and
should not be larger than seven millimeters.
[0087] In FIGS. 8 and 9, there are shown a plan view and a right
elevational view of the embodiment of FIG. 7, respectively, showing
the slot 120 having a width of 0.008 inch and extending downwardly
approximately 0.07 inch. As best shown in FIG. 8, the edges of the
walls of the tube or sleeve 18B along the slot 120 have a larger or
blunter trailing edge shown at 126 and a sharper leading edge shown
at 124 in one embodiment as well as a blunter edge shown at 130 and
a sharper edge shown at 128 so that the sharper edges 124 and 128
as the item rotates counter-clockwise as shown in FIG. 8 looking
into the surface of the drawing elongate or cut the tissue within
the eye and create cavitation at the blunter edges 130 and 126.
[0088] In FIG. 10, there is shown a fragmentary, front elevational
view of another embodiment showing the tip 24 along the slot 120A
brought together, welded and offset to provide a sharper and a
blunter edge by offsetting the edges along the slot 120A to a
greater degree but without the need for changing the thickness of
the tube walls. This embodiment forms a rake angle of 90 degrees
and two cutting edges, but slots at three locations in the wall of
sleeve 18B can also be formed instead of two slots 180 degrees
apart, providing a 60 degree rake angle and three cutting edges, or
four slots can be formed to provide a 45 degree rake angle and four
cutting edges. Moreover, the tips can be brought together as in
FIG. 10 to form a smooth protective dome or can include a cutting
edge or be open. The tip can also be twisted, which will change the
rake angle along the slot and provide a cyclone fan pulling
effect.
[0089] To form the embodiments of FIGS. 7-10, a tubular sleeve 18B
is slotted at 120 as shown best in FIGS. 11 and 12 and pinched
together. The two sides are then offset in space laterally in a
direction along a plane passing through the center of the slots and
the longitudinal axis of the sleeve as shown in FIGS. 13 and 14 and
the tips pinched together and brazed together to form a tip such as
that shown in FIG. 10. Prior to closing the tips 24, the narrower
and blunter edges may be further shaped by cutting one wall at a
more acute angle than the other wall and then removing the other
sides of the slot with a reverse cut to form flat ends and
sharpened ends.
[0090] To form other raking angles and/or shape the blade to pull
viscous fluid, the ends are offset, twisted and brazed as shown in
FIG. 15 and 16, first offset along a line or plane aligned with the
two slots and longitudinal axis and then twisted at a slightly
different angle to form a different rake angle and to create a
cyclone pump effect. The tip is normally smooth at the very tip 24
but has a cutting effect as it moves radially outwardly.
[0091] In one version of the preferred embodiment, the tube 18B has
an outer diameter of 42 thousandths (0.042) inch with two
diametrically opposed slots. The ends are moved together in a
curvature leaving a slot about eight thousandths inch wide at its
widest point and extend from the top approximately 70 thousandths
inch (70 thousandths long). Ninety degrees removed from the two
slots are central aspirating apertures having a diameter of 18
thousandths of an inch and being circular in cross section. They
are located with their bottom edge generally adjacent to the end of
the slots.
[0092] The tube usually rotates at approximately 1600 hertz when
fragmenting the nucleus in a preferred embodiment having two
cutting edges and the wedged surfaces of the slots have one edge
that is in a range of one thousandths of an inch to 20 thousandths
of an inch thick and a trailing edge that is in the range of ten
thousandths of an inch to 50 thousandths of an inch thick.
Preferably, it should be in the range of 300 hertz to 4000 hertz
but may be slower or faster when at a location in the capsular sac
not near tissue to be preserved or which may be moved to change
other tissue. The slots and rate of rotation are selected to
provide, in the preferred embodiment, a surface moving 200
centimeters a second at the fastest point on the curved moving
surfaces and preferably to provide a surface moving at the fastest
point within a range of five meters a second to 40 centimeters per
second at the fastest point but may move slower or faster under
some circumstances.
[0093] Since it is a rotating surface which curves inwardly toward
the center, the speed is very low at the center and, under some
circumstances, does little fragmenting at the center and more and
more fragmenting as the rotating radius increases to the sleeve
radius. The slot is next to tissue for a very short time such as
between 10 milliseconds and 1 millisecond. Each cutting edge sweeps
past a point about once every 625 microseconds, preferably, or in
the normal range of once every 3 milliseconds to once every 400
microseconds.
[0094] In addition to zones of a sphere and sections of a cylinder
intended for use within an eye, other shapes of moving surfaces may
be used and the tool has uses other than for cataract removal, such
as in vascular operations. For example, multiple zones of a sphere
may be spaced from each other at a shorter distance so that the
item need not be rotated as fast and motion other than rotational
motion may be used to prevent entrance of the tissue into the
fragmenting zone. A convenient embodiment for removing structures
around veins or arteries during vascular operations is dumbbell
shaped so that a recess fits around the vein while spherical
cutting zones are positioned on either side of the vein.
[0095] In some embodiments, the moving surface is formed of a
curved member attached to a rotatable shaft having a sharpened edge
at an angle of between 0 and 60 degrees but preferably 45 degrees
with a surface of revolution, which surface has a center of
rotation aligned with the rotating shaft. The sharpened edge of the
curved member may face away from the center of rotation so that the
cutting action of the sharpened surface is into the cortex and core
material of a cataract.
[0096] In FIG. 17, there is shown a block diagram generally
illustrating the steps in a cataract extraction and lens
implantation technique 50 comprising: (1) the step 52 which
includes the preliminary substeps of maintaining the anterior
chamber and making the incision into the capsular wall; (2) the
step 54 of removing the lens by fragmenting it and aspirating it
with the rotating member; and (3) the step 56 which includes the
substeps necessary for implanting the lens.
[0097] In performing this technique, the step 52 which includes the
substeps required to make the incision and maintain the anterior
chamber and the step 56, which includes the substeps necessary for
implanting the lens are not by themselves new and many of the steps
are described in Anis, Aziz Y., "Illustrated Step-by-Step
Description of the Anis Dry Extra Capsular Cataract Extraction
Technique With In-the-Bag Lens Implementation", Seminars in
Ophthalmology, v. 1, N. 2 (June), 1986, pp. 113-129. Moreover, the
removal of the lens may not be followed by implantation but may be
part of a treatment in which the aphakia is treated by contact lens
or glasses.
[0098] The step 54 of removing the lens by fragmenting and
aspirating it with the rotating member includes: (1) the step of
inserting the handpiece; (2) the step of breaking and removing the
hardened part of the nucleus; and (3) the step of aspirating
particles of tissue. These steps are all performed through a small
incision while the anterior chamber is maintained with a
viscoelastic medium. Hydrodelineation may be performed as described
in U.S. Pat. 4,908,015, if desired, but such hydrodelineation is
not part of this invention. If necessary, vitreous fluids may be
aspirated.
[0099] The step 52 which includes preliminary substeps of
maintaining the anterior chamber and making the incision in the
capsular wall includes the substep of making a small incision in
the capsular bag, preferably no greater than three millimeters in
length and in the range of one to two millimeters. This incision is
made while the anterior chamber is maintained and is made as small
as possible to maintain the structure of the capsular bag to the
extent possible. Through this small incision, the step 54 of
fragmenting and aspirating and the step 56 of implanting a lens are
performed. Under some circumstances, the incision may be four or
five millimeters but should always be less than 7 millimeters.
[0100] With the posterior capsule in focus in the focal plane of
the microscope, the handpiece 10 is introduced through an incision
shown at 220 in FIG. 18 in the wall of the capsular sac. The tip of
a handpiece 10 is thrust through the incision in the wall of the
capsular bag and into the lens therein.
[0101] The tip is rapidly rotated and linearly vibrated in a
direction normal to the plane of rotation while slight negative
pressure is applied to aspirate the fragments. The rotating tip is
inserted gradually into the cortex and nucleus and, from time to
time, a small amount of irrigating fluid is injected. Fragmented
cortex or nucleus material is aspirated. The speed of rotation and
vibration can cause the particles to be so fine as to be
substantially invisible and not to interfere with visibility of the
surgery. The rotation and aspiration mix the small particles and
easily pull them into the instrument. The same handpiece can be
used to remove vitreous fluids. After removal of the cataract and
the handpiece with the capsular sac relatively intact, a lens
implant is inserted through a relatively small opening as described
in the above publication of Anis.
[0102] Generally, the nucleus is first removed then the cortex. The
surface-discriminating, fragmenting handpiece fragments and permits
aspiration of the cortex and nucleus without damaging nearby smooth
walls of the capsular sac. It avoids fragmenting the smooth walls
with its cutting edges but fragments rougher, stiffer higher-mass
tissue, moving it into a negative pressure zone for aspiration. The
smooth more flexible, lower mass surfaces are moved by the blades
which hit it at an angle. The tissue being fragmented is hit at an
angle and is subject to cavitation rapidly and repeatedly with a
force each time that does not move the entire material to the
extent that it may damage the capsular wall or other healthy tissue
that is not to be fragmented but does fragment the cortex.
[0103] The surface discrimination of the instrument is controlled
by moving surfaces which permit the diseased higher-mass tissue to
be fragmented but which move at a rate of speed and have openings
between them of such a size that the more integrated flexible,
lower-mass and smoother tissue does not fall within their
fragmenting zone. The tissue is not constrained by opposed shear
forces of the instrument but are free to move and the cutting edge
of the instrument cuts tissue that: (1) is stiffer and has a higher
modulus of rigidity; and (2) is at an angle to the cutting edge
closer to 90 degrees and receives less force moving it away.
[0104] Thus, the surgeon removing a cataract adjusts the speed of
movement of the cutting edge to cut cortex with a higher-mass and
modulus and more projections in the path of the cutting surface and
not the capsular wall with a lower modulus and mass and fewer
projections closer to 90 degrees so it is more readily moved away
from the cutting edge. The aspirating pressure is low enough to
pull the fragmented tissue but not the smooth wall. The rotating
surfaces move the smooth wall outwardly and provide some counter
pressure to the aspirating pressure inside the cutting zone.
[0105] In using this instrument, as the lens is reduced in mass and
freed from its connection to the structure of the eye by
fragmentation, its tendency to move away from the cutting edges is
increased. One way of compensating for this effect may be by
changing the speed, the location and the direction in which the
cutting edges impact the lens sufficiently often to neutralize the
tendency of the impact to move the lens in one direction. Another
aid is to rotate the tip to mix the particles with fluid and pull
the fluid and particles into the instrument. This is done by
continuously rotating the tip in one direction while ultrasonically
vibrating it. Continuous rotation in one direction means rotation
in one direction for more than one 360 degree cycle of rotation.
Without such rapid impact, the impacting may cause the lens to
move, such as by causing rotation of the lens.
[0106] In FIG. 19, there is shown a fragmentary, partly diagramatic
and partly longitudinally sectioned view of still another
embodiment of handpiece 10B especially useful after the lens has
been reduced in size. Instead of being operated by a dental drill
motor 40, it is driven by a vibrator 40A, which may be any
conventional type of vibrator such as those used to operate the tip
in the above-mentioned U.S. Pat. Nos. 3,589,363 to Anton Banko, et
al., 3,902,495 to Steven N. Weiss, 3,693,613 to Charles Kelman, et
al, and 4,041,947 to Steven N. Weiss, et al. Except for the drive
mechanism, the handpiece 10B is identical to the embodiment of FIG.
6 and the reference numbers for identical parts remain the
same.
[0107] The handpiece 10B includes, in addition to the
aforementioned vibrator 40A, an aspirating drive sleeve 18B, an
outer housing 60 and a motor-tool sleeve coupling 62 with: (1) the
vibrator 40A being connected to the drive sleeve 18B through the
coupling 62 and being located within the outer housing 60; (2) the
sleeve 18B extending outwardly thereof for vibrating curvalinear
motion by the vibrator 40A through the coupling 62 during operation
of the handpiece 10B.
[0108] The vibrator 40A includes a conventional oscillator 130, a
source of dc power 132, and a piezoelectric or electromagnetic
vibrator 134 electrically connected in series with the switch 20
(FIG. 1) to be energized and vibrate the cutting edges (not shown
in FIG. 19) connected to the sleeve portion 12C as explained in
connection with the embodiment of FIG. 6. A shaft 90A is mounted
for rotation in bearings 138 and includes a welded arm extending
orthogonally and radially therefrom, biased into contact with or
fastened to a movable portion of the vibrator 134 so that vibration
of the vibrator imparts rotating motion to the shaft 90A.
[0109] To connect the vibrator 40A to the sleeve portion 12C, the
motor-tool sleeve coupling 62 includes the vibrator output shaft
90A, a cylindrical boss 92, a cylindrical support member 94, an
annular groove 96 within the support member 94, two counterbores 98
through the support member 94 at the bottom of the annular groove
96, an opening 100 communicating with the aspirating connector 76
and extending through the cylindrical support 94, a cylindrical
opening 95 sized to receive the sleeve 18B and a brazed connection
102 more firmly fastening the support member 94 to the sleeve
18B.
[0110] The bearing support 101 receives the vibrator shaft 90A and
the boss 92 which rotationally vibrate within it and are supported
by it. The groove 96 communicates with the opening 100 as it moves
because of its annular shape and receives vacuum pressure which it
transmits through the counterbores 98 into the sleeve 18B to create
negative pressure in the working tip through this elongated
sleeve.
[0111] With this arrangement, closing the switch 20 (FIG. 1)
connects power from the power supply 132 to the oscillator 130. The
vibrator 134 then vibrates at the frequency to which the oscillator
130 has been tuned by the surgeon, which vibrator 134 being
energized through conductors 139. The vibrator 134 reciprocates a
lever 136 turning the shaft 18B repeatedly. This causes the lens to
be impacted with the cutting edges at an angle and speed that
avoids damage to the capsular wall, if it should be near, and
fragments the lens.
[0112] In FIG. 20, there is shown a partly longitudinally
sectioned, fragmentary, simplified view of a handpiece 10C, having
as its principal parts an ultrasonic vibrator 40C, an electrical
rotational motor 40D and a aspirating tube 18C all in line with
each other along a common longitudinal axis. The motor 40D is
coupled to the ultrasonic vibrator 40C, which in turn is coupled to
the aspirating tube 18C to impart a combined rotary and
longitudinal ultrasonic reciprocating motion to the aspirating tube
18C.
[0113] With this mechanism, the aspirating tube 18C moves the
fragmenting tip 14C (not shown in FIG. 20) so that it rotates
rapidly, and while rotating, ultrasonically vibrates in and out of
the tissue once for each small, angular increment of rotational
motion, such as for example, every one degree or less. Thus, it
combines the rotational movement and ultrasonic movement of prior
embodiments. While the motor 40D is intended to continuously rotate
the aspirating tube 18C in a single direction, such as clockwise or
counterclockwise, it can alternate rotations, between clockwise and
counterclockwise in the manner of the embodiment of FIG. 19. In
this manner, the time of impact is primarily determined by the
frequency of the ultrasonic, reciprocal motion and the location and
direction are primarily controlled for a stationary handpiece by
the rotational speed. By selecting the optimum or near optimum
values of rotational speed and reciprocating frequency, movement of
the mass of tissue with respect to fragmenting speed may be
controlled.
[0114] The embodiment 10C of FIG. 20 is similar to prior
embodiments in that it includes a tubular aspirating connector 76
and an irrigating connector 74 to aspirate through the center of
the aspirating tube 18C and irrigate between the protective sleeve
1 2D and the aspirating tube 18C in the manner described in
previous embodiments. In the embodiment of FIG. 20, the outer
housing 60C encloses both an ultrasonic vibrator 134 (FIG. 19)
adapted for reciprocally vibrating the aspirating tube 18C to which
the fragmenting tip is connected in a direction aligned with the
longitudinal axis of the handpiece 10B and the tip and the
rotational motor 40D coupled through a coupled mechanism 150. The
necessary electrical connections are supplied through an opening in
a rear bulkhead 152.
[0115] In FIG. 21, there is shown a fragmentary, sectional view of
another embodiment of fragmenting tip 14C having tubular,
cylindrical walls 164 enclosing an aspirating section 162, which
communicates with the interior of the aspirating tube 18C (FIG.
20). The end of the tip 14C is rounded at 158 and in one
embodiment, may be roughened. An opening 156, communicates with the
aspirating section 162 and provides a slight, inward pull of
tissue.
[0116] To fragment tissue, the opening 156 forms a leading edge and
a cutting edge in the walls extending below the rotating portion.
This opening may be extended to different depths as desired for
determining the area of cavitation. Moreover, there may be a slot
in one side of the tubular walls 164 communicating with the
aspirating section 162 of the fragmenting tip 14C but also, the
cavitating edges may be only cut partway into the walls 164 rather
than entirely through the walls along their entire length or
through only a portion of their length. The slot provides an
opening for receiving tissue particles although an opening in
conjunction with an edge formed on the surface without penetrating
into the aspirating section 162 of the tube may serve the same
function.
[0117] In operation, the tube 18C is rotated while ultrasonic
vibrations are applied along its rotational axis so that it
reciprocates in and out of tissue a large number of times for each
rotation. For example, the rotation may be between 100 and 15,000
revolutions per minute and preferably between 4,000 and 5,000
revolutions per minute while the ultrasound vibrations may be
applied within a range of 10 kilohertz to 500 kilohertz and
preferably 40 kilohertz. The exact frequency of reciprocating
vibration and rotational speed may be selected by the surgeon and
may even extend to lower speeds and frequencies or higher speeds
and frequencies depending on the nature of the cataract being
fragmented. The tip of the tube should be symmetrical rather than
chisel shaped so as to be visible when rotating and reciprocating
and may have a continuous distal edge but must be shaped to remove
tissue by cavitation.
[0118] The frequency of vibration and the speed of rotation are
selected so that the tip moves inwardly into the tissue at every
small fraction of rotation, such as at every degree of rotation to
not impart excessive motion to the mass of the tissue but to cause
removal of the tissue as a fine powder.
[0119] The combined integrated technology of this surgical tool
provides added convenience and functions normally in separate
available surgical handpieces. Size reduction due to advancing
technology, in conjunction with the physician's desire for smaller
surgical wound sites and precision tissue removal, allow this
handpiece to incorporate both rotary action and ultrasonic
fragmentation. It permits vitrectomy and removal of fragmented
cataract with the same handpiece tip. When operating at 40 kHz
(which is the most commonly effective frequency for ultrasonic
systems), this handpiece delivers 0.012 inch of stroke
displacement. The constant stroke feature provides consistent power
through any hardness of tissue.
[0120] The rotary action assists the ultrasonic fragmentation of
the tissue, by tumbling the fractured particles at the distal end
of the ultrasonic tip. This allows the tip to acquire a new surface
of tissue without the need for a second manipulation instrument.
This allows smaller "bites" and reduces propensity for "coring" or
"plunging" and subsequent particles are aspirated through the
ultrasonic tip.
[0121] The added fluid action from the rotation enhances a "capture
zone" forming a larger funnel shaped suction pattern that enhances
flow to the tip. Just outside this region is a turbulent zone that
rejects (protects) tissue. The speed of rotation increases or
decreases this action. Working in conjunction with the aspiration
and infusion, the rotation enhances the ultrasonic action.
[0122] In FIG. 22, there is shown a block diagram of an interface
170 between a phacotmesis handpiece 10C and any one of a plurality
of incompatible consoles 21A which consoles may be electrically
incompatible with the phacotmesis handpiece 10C. The consoles 21A
may be of the type used for a hydrosonic type of ocular operation
or phacoemulsification type of ocular operation.
[0123] For this purpose, the interface 170 includes a handpiece
simulator 174, a power supply 176, an ultrasonic driver 178, and a
motor driver 180. The power supply 176 and the motor driver 180 are
conventional. The power supply 176 is adapted to be connected
through conductors 172 to conventional power mains. It supplies DC
power to the handpiece simulator 174, the ultrasonic driver 178 and
the motor driver 180 through the conductor 182.
[0124] The handpiece simulator 174 is electrically directly
connected to the console 21A and matches the output impedance of
the console to the imput impedance of the handpiece to obtain
efficient power transfer of the control signal from the console to
the drivers. The fluidic connections are connected directly from
the console 21A to the phacotmesis handpiece 10C since they are
generally compatible. The console 21A and the handpiece simulator
174 together provide the appropriate signal to determine at least
the amplitude of ultrasonic vibration by the ultrasonic driver 178.
The frequency of the ultrasonic vibrations and the rate of rotation
by the motor driver 180 may be set on the handpiece 10C or by the
synergist and may or may not be varied by signals from the console
21A depending on the design of the instrument and console.
[0125] To enable the connection of a plurality of different
consoles to a phacotmesis handpiece 10C, the handpiece simulator
174 includes a rotary switch that is adapted to interconnect any
other of a plurality of different impedances to the input
connectors leading to the console 21A, with the input impedances
being selected to match the output impedances of the different
consoles. Instead of utilizing control signals from the console
21A, the interface 170 may include individual, manually, adjustable
attenuation devices or amplifiers to control the ultrasonic driver
178 and the motor driver 180 individually to set rates of
ultrasonic vibration of the tip and corresponding rates of rotation
of the tip or a combination of the two from a single switch.
[0126] In FIG. 23, there is shown a schematic circuit diagram of
the handpiece simulator 174 having an input transformer 190, lumped
parameter impedances 192, a selector switch 194, and output
terminals 196. The transformer 190 is adapted to have its primary
electrically connected to a console 21A (FIG. 22) and the output
terminals 196 are adapted to be electrically connected to the
ultrasonic driver 178 (FIG. 22) and to the motor driver 180 (FIG.
22). The lumped parameter impedances 192 and the selector switch
194 are adapted to be electrically connected in circuit with each
other and between the transformer 190 and the output terminals 196.
The switch 194 may be open to disconnect the console, closed to a
first terminal to connect one value of impedance or to a second
terminal to electrically connect in circuit a second impedance so
that the handpiece simulator 174 may provide an input impedance
which matches the output impedance of a console to which the
handpiece is intended to be connected.
[0127] In FIG. 24, there is shown a block diagram of an ultrasonic
driver 178 having input terminals 200, a high voltage power supply
202, a variable power supply 204, a tuning module 208, a power
amplifier 206, an impedance matching network 210 and output
terminals 212. The input terminals 200 are electrically connected
to the handpiece simulator 174 (FIG. 22) to receive control
signals. These control signals are applied to drive the DC motor
driver 180 (FIG. 22) and are applied to the power amplifier 206 and
the variable supply 204. The variable power supply 204 receives
power from the high voltage supply 202 and supplies a selected
voltage to the power amplifier 206 under the control of the control
signal through input terminals 200. This signal determines the
amplitude of the signal applied to the impedance matching network
210. The frequency of that signal is adjusted by the tuning module
208 under the control of a computer or the direct control of a
surgeon. The output from the matching network 210 drives the
ultrasonic vibrator and the handpiece 10C (FIG. 22).
[0128] In use, the interface is connected to a console and to the
phacotmesis handpiece and the rotary switch is switched to the
appropriately labeled console to provide efficient power transfer
by impedance matching. In the preferred embodiment, the control
signal from the console is used to control both the rotational
speed and the vibration speed.
[0129] After preparation for phacotmesis, the lens is preferably
grooved to form three delineated sections. This may be done by a
first groove made in the lens of the eye which is then bifurcated
by two grooves, using the phacotmesis instrument described above
with the ultrasonically vibrating and rotating tip extending
slightly, such as zero to two millimeters beyond the distal end of
the irrigating sleeve. After the first groove is made, the nucleus
is fractured such as by cracking forceps, then the second groove is
made in the larger fragment and that fragment is fractured.
[0130] The phacotmesis tip is then retracted slightly until it is
level with the irrigation sleeve. It may extend slightly for very
hard lens material and may be retracted slightly for soft lens
material but is approximately level. The tip is then positioned on
a surface of one of the fragments and held by occlusion. The
phacotmesis tip is activated and the resulting fragments are
one-by-one aspirated.
[0131] As can be understood from the above description, the
technique and equipment of this invention has several advantages,
such as: (1) they selectively fragment some tissue without damaging
other nearby tissue; and (2) they are able to fragment, mix and
aspirate tissue, and in the case of cataract removal, also scrub
the capsular wall without damaging it, all with one instrument.
[0132] Although a preferred embodiment of the invention has been
described with some particularity, many modifications and
variations are possible in the preferred embodiment without
deviating from the invention. Therefore, it is to be understood
that within the scope And of the appended claims, the invention may
be practiced other than as specifically described.
* * * * *