U.S. patent number 3,659,607 [Application Number 05/025,669] was granted by the patent office on 1972-05-02 for method for performing surgical procedures on the eye.
This patent grant is currently assigned to Surgical Design Corporation. Invention is credited to Anton Banko.
United States Patent |
3,659,607 |
Banko |
May 2, 1972 |
METHOD FOR PERFORMING SURGICAL PROCEDURES ON THE EYE
Abstract
The method relates to performing surgical procedures on the eye
in vivo, including forming of an opening therein to permit the
insertion of instrumentation within the eye for various
procedures.
Inventors: |
Banko; Anton (Brooklyn,
NY) |
Assignee: |
Surgical Design Corporation
(Long Island, NY)
|
Family
ID: |
26700013 |
Appl.
No.: |
05/025,669 |
Filed: |
April 6, 1970 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
762286 |
Sep 16, 1968 |
3528425 |
|
|
|
Current U.S.
Class: |
606/169;
606/170 |
Current CPC
Class: |
A61F
9/00745 (20130101); A61B 17/32002 (20130101); A61B
17/34 (20130101); A61B 2017/320084 (20130101); A61B
2217/007 (20130101); A61B 2017/00685 (20130101); A61M
39/0247 (20130101); A61B 2017/346 (20130101); A61M
3/0279 (20130101); A61B 2017/3492 (20130101) |
Current International
Class: |
A61B
17/34 (20060101); A61B 17/32 (20060101); A61F
9/007 (20060101); A61B 17/00 (20060101); A61M
3/02 (20060101); A61M 3/00 (20060101); A61M
1/00 (20060101); A61b 017/32 () |
Field of
Search: |
;128/1R,303,305,329,347 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pace; Channing L.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This is a division of application Ser. No. 762,286, filed Sept. 16,
1968, now U.S. Pat. No. 3,528,425 dated Sept. 15, 1970.
In applicant's co-pending application Ser. No. 760,003, filed on
Sept. 16, 1968, and which entire subject matter of the co-pending
application is incorporated herein by reference as if fully set
forth herein, applicant discloses the method and apparatus for
performing retina reattachment procedures using ultrasonic energy
in which the opening in the eye may be formed in accordance with
the teachings of the present invention.
Claims
I claim:
1. The method of positioning instruments within the eye comprising
the steps of:
Positioning a supporting means having a passage therethrough
adjacent a selected area of the outer wall of the eye,
Moving a cutting means into the wall of the eye within said
selected area to pierce said wall and form an opening therein,
Moving said supporting means with said cutting means into said
opening so that a portion of said supporting means extends through
the wall of the eye to provide access for an instrument into the
interior of the eye through the passageway of said supporting
means.
2. The method of claim 1 further comprising the step assembling the
cutting means to the supporting means to move therewith prior to
moving said cutting means into the wall of the eye so that said
cutting means and supporting means can be moved together, and
moving said cutting means and said supporting means so that said
cutting means first forms the opening and the supporting means is
thereafter moved through said opening.
3. The method of claim 2 wherein said assembling step comprises
placing said cutting means through the passageway of said
supporting means.
4. The method of claim 3 further comprising the steps of
withdrawing said cutting means through said passageway of said
supporting means and inserting an instrument into the eye through
said passageway.
5. The method of claim 1 further comprising the step of mounting
said supporting means to the wall of the eye.
6. The method according to claim 3 further comprising the steps of
releasably locking said cutting means to said supporting means with
said cutting means positioned within said passageway of said
cutting means and having a cutting surface extending beyond the
front of said supporting means, and moving said assembled cutting
means and supporting means to first force the cutting surface of
said cutting means into the wall of the eye to penetrate the wall
to form the opening for receiving said supporting means and then
move the supporting means into the opening.
7. The method according to claim 6 further comprising the steps
of:
unlocking said cutting means from said supporting means,
removing said cutting means from said passageway, and inserting
instrumentation through said passageway into the interior of the
eye.
8. The method according to claim 1 further comprising the step of
retaining said supporting means in fixed axial position relative to
the wall of said eye.
9. The method according to claim 1 further comprising the step of
forming a seal between the opening formed by said cutting means and
the supporting means extending therethrough to prevent the escape
of the vitreous material contained within the eye through said
opening.
10. The method according to claim 9 wherein the step of forming
said seal includes applying at least one suture through the wall of
the eye in surrounding relation to said supporting means.
11. The method according to claim 1 further comprising the steps
of:
a. inserting an instrument through said passageway, and
b. sealing said instrument within said passageway to prevent the
escape of the vitreous material contained within the eye through
said passageway.
12. The method according to claim 11 further comprising the steps
of:
a. removing said instrument from within said passageway,
b. inserting in said passageway means for removing said supporting
means, and
c. moving said removing means outwardly from the eye for
disengaging said supporting means from the wall of the eye.
13. The method of positioning instrumentation within the eye
utilizing cutting means having a cutting surface, and supporting
means having a passageway extending therethrough, comprising the
steps of:
A. releasably assembling said cutting means with said supporting
means such that said cutting means extends within said passageway
and said cutting surface extends beyond the front end of said
supporting means,
B. forcing said assembled supporting means and cutting means
through the wall of the eye with said cutting surface first
penetrating the wall of the eye to form an opening therein, and
continuing said force until said supporting means extends through
the wall of the eye,
C. disassembling said cutting means from said supporting means,
D. removing said cutting means from said passageway, and
E. inserting through said passageway the instrumentation.
14. The method according to claim 13, and including the step of
sealing said instrumentation within said passageway to prevent the
escape of the vitreous material contained within the eye through
said passageway.
15. The method according to claim 13, and including the steps
of:
a. removing said instrumentation from within said passageway,
b. inserting in said passageway removing means in sealing
engagement therewith, and
c. disengaging said supporting means from the wall of the eye.
16. The method according to claim 13, and including the step of
forming a seal between the opening and the supporting means
extending therethrough to prevent the escape of the vitreous
material contained within the eye through said opening.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to improvements in surgical
procedures related to the eye, and more particularly for forming an
opening in the eye to permit the insertion of instrumentation
therein.
The outstanding and unexpected results obtained by the practice of
the method and apparatus of the present invention, are attained by
a series of features, steps and elements, working together in
inter-related combination, and may be applied to biological
organisms in general and particularly humans, and hence will be so
illustrated and described.
Applicant has found that in order to perform various exploratory,
diagnostic, or other surgical procedures with respect to the eye,
it is necessary for an incision or opening to be formed through the
wall thereof such that the instrumentation necessary might be
inserted therethrough. When the procedure intended is completed it
then becomes necessary to close the opening and permit the incision
in the wall of the eye to properly heal such that the eye might
function in a proper manner. In applicant's copending patent
application referred to above, the process of retina reattachment
is disclosed, and in which an incision might be formed in
accordance with the present invention. To facilitate the discussion
of applicant's invention dealing with the formation of the incision
reference is made to the copending application to merely illustrate
one form of surgical procedure that might be conducted after the
opening is made as hereinafter described in detail.
By way of illustration and not limitation, once the incision has
been made in accordance with the present invention and a passageway
formed from the interior to the exterior of the eye then a variety
of instruments besides an ultrasonic probe, may be inserted within
the passageway to accomplish physical tasks or transmit information
to the trained individual from within the eye. For example, a two
way bundle of fibers, of which one set is used for the illumination
of the interior of the eye and the other set in the bundle is used
to carry the image back to the viewer may be utilized. This permits
a thorough inspection of the interior of the eye before and after
any operation is performed. An instrument may be inserted through
the passageway for removing blood clots and other impurities from
vitreous material contained within the eye. Instrumentation may
also be utilized for replacement of lost or spoiled vitreous
material. An instrument may be utilized for cutting membranes and
bands tracting the retina. An instrument may also be utilized to
force the subretinal fluid (vitreous) into the eye, and the retina
to settle back against the choroid. An ultrasonic or other cautery
for sealing retinal vessels causing hemorrhage into the vitreous or
aqueous of the eye may also be used. Essentially, in all of these
related illustrated procedures it is necessary that a proper
sclerotomy be formed such that after the necessary time is required
for carrying out the procedure the incision may be closed to permit
a proper healing thereof.
Before proceeding to the details of the invention, let us first
review briefly generally known facts of the eye, and the anatomy of
the retina. The retina of the eye is attached to the underlying
choroid at the optic nerve border posteriorly and at the ora
serrata anteriorly. Between these two points it is in contact with
but not attached to the choroid. The retina covers the entire inner
aspect of the eyeball posterior to the ora serrata. The ora serrata
is the junction of the retina and the ciliary body, in the average
eye it is about 8 mm posterior to the limbus. The retina is
composed of inelastic nerve tissue, consisting of ten distinct
different layers, normally it is transparent, when detached it
appears gray. Most common of retina detachment is the partial
separation (detachment) of the retina from the choroid. The
superior temporal part of the retina is most commonly affected, but
any part or even the entire retina may become detached. According
to this invention before the reattachment of the retina may take
place an opening must be formed permitting the insertion of the
required instrumentation.
OBJECTIVES OF THE INVENTION
An object of the present invention is to provide an improved method
and apparatus for performing surgical procedures with respect to
the eye.
Another object of the present invention is to provide an improved
method and apparatus for forming an incision with respect to the
wall of the eye.
Another object of the present invention is to provide an improved
method and apparatus to form an incision in the wall of the eye
that permits the introduction into the eye of a variety of
instrumentations that may be used for exploratory, diagnostic and
surgical procedures.
Another object of the present invention is to provide an improved
method and apparatus for opening the eye and subsequently
introducing instrumentation therein and maintaining the
instrumentation in sealing engagement so as to prevent the loss of
vitreous material therefrom.
Other objects and advantages of this invention will become apparent
as the disclosure proceeds.
SUMMARY OF THE INVENTION
The present invention is directed to the formation of an opening in
the eye such that a passageway is formed through which various
instruments may be inserted within the eye to perform exploratory
or surgical procedures which may be of a diagnostic or therapeutic
nature. The sclerotomy or opening that is formed is based on the
fact that it is possible with specially designed cutting means and
supporting means, assembled together, to insert them through the
wall of the eye such that an opening is formed. The cutting element
is designed to puncture the wall, which is composed of a number of
layers, when a static force is applied thereto. The supporting
means has retaining means associated therewith such that in its
seated position through the wall it is in interlocking relationship
with the wall such that the cutting element may then be
disassembled from the supporting means and retracted. The
supporting means has a passageway extending therethrough which
permits the insertion of various tools and instruments into the
eye. The supporting means is provided with one or two
conventionally applied sutures such that it is retained in sealing
engagement with the wall to prevent any leakage therethrough. The
passageway may contain therein sealing means in the form of an
o-ring which is capable of preventing any of the material from
flowing thereout as an instrument is inserted therein.
The cutting element is designed to have a conically pointed
puncturing surface having spaced apart cutting edges such that it
has the ability to severe and separate the adjacent wall portions
as it is forced through the wall thereof. The cutting element acts
as a two edged knife designed to start an incision and enlarge it
to the proper length which thereafter continues until the
supporting means reaches its seated position and held fast by the
retaining means associated with the supporting means.
In practicing the invention, after the completion of the necessary
procedure, the supporting means may be removed by first inserting a
removing means that may be interlocked with the supporting means
and after the sutures are loosened it may be removed by applying a
static force outwardly directed from the eye to disengage the
retaining means. The removing means also acts to increase the
pressure in the eye thus reducing the clamping force around the
supporting means, facilitating its removal. The sutures need only
be loosened and as the supporting means is retracted they may be
progressively tightened to continuously close the adjacent edges of
the incision keeping the eye wall in sealed engagement with the
outgoing removing means.
BRIEF DESCRIPTION OF THE DRAWINGS
Although the characteristic features of this invention will be
particularly pointed out in the claims, the invention itself, and
the manner in which it may be made and used, may be better
understood by referring to the following description taken in
connection with the accompanying drawings forming a part hereof,
wherein like reference numerals refer to like parts throughout the
several views and in which:
FIG. 1, is a somewhat schematic view of an ultrasonic motor
generator system for driving a tool member inserted in the eye
through an opening formed in accordance with the present
invention;
FIGS. 2 and 3, are greatly enlarged views, partly in section,
illustrating the formation of an opening through the wall of the
eye;
FIG. 4, is a view similar to FIG. 3, showing an instrument
extending through the opening into the eye for performing various
procedures;
FIG. 5, is a view similar to FIG. 3, showing the removal of the
supporting means from within the opening to permit its closing;
FIG. 6, is a side elevational view of the cutting means used to
form the opening in the eye;
FIG. 7, is a top view of the cutting means illustrated in FIG. 6;
and
FIGS. 8-14, are cross-sectional views taken along the respective
section lines in FIG. 7.
DETAILED DISCUSSION OF THE DRAWINGS
Referring now to the drawings and particularly to FIG. 1 thereof,
we see the schematic representation of an eye 10 having the various
portions thereof including a retina 12, in a particular area 14
with spaced apart detached portions 16 and 18 from the choroid 20.
The area 14 is detectable in a conventional manner such that the
surgeon is aware of its location and will conduct the operation
with the intent to rejoin the detached portions, or portion, to the
choroid 20 without substantially, if at all injuring the associated
parts thereof including the sclera 22. The wall 25 is intended to
define any portion of the eye which when pierced will connect the
interior of the eye to the exterior and will generally include all,
or portions, of the retina 12, choroid 20 and sclera 22, or the
sclera 22 and ciliary body 24.
Once the partial separation, or detachment of the retina 12 from
the choroid 20 is detected, and this generally occurs with respect
to the superior temporal part of the retina which is most commonly
affected, but any part or even the entire retina may become
detached, then the reattachment of the retina is accomplished in
accordance with the teachings of applicant's copending patent
application. Briefly this includes first forming an incision or
opening 27 in the eye 10, in accordance with the present invention,
to permit the insertion of instrumentation in the form of a probe
30 therethrough to reach the specific area to be treated. The
opening 27, as hereinafter described in greater detail, is capable
of being used not only for the reattachment of the retina but for
various other operative procedures and uses hereinabove disclosed,
both with the eye and other portions of the anatomy and is
accordingly so described and intended.
Once the opening 27 is formed the probe 30, or other
instrumentation, is inserted therein such that the tip or distal
end 32 thereof, which is the vibratory surface, is positioned
within the vitreous material 34 contained in the eye 10 and the
vibrational wave energy may be propagated through the vitreous
material 34 to obtain a joining or a bonding of the detached
portions 16 and 18 to the wall 25, such as the choroid 20 and the
sclera 22. The vibrational wave energy or ultrasonic energy as the
terms are herein used, is intended to include vibratory energy in
the frequency range of from 1,000 cycles per second to 20,000,000
cycles per second although the preferable range is generally from
10,000 cycles per second to 1,000,000 cycles per second.
Referring further to FIG. 1, it will be seen that the
instrumentation in the form of probe 30 for ultrasonically
performing surgical procedures on a biological organism, such as a
human, may include an ultrasonic transducer or motor 35 for
effecting the necessary high frequency vibrations of the vibratory
element or tool member 36 with the distal end or output surface 32
transmitting the vibrations. The ultrasonic motor 35, as
illustrated may be in the form of a driving member adapted for
being hand held as by an operator 38, and generally comprising a
tubular housing or casing 40 into which an insert unit supporting
the vibratory element 36 may be partially telescoped. The
ultrasonic motor 35 is energized by an oscillation generator 42,
with a power cable 44, connecting the two together. The generator
is an oscillator adapted to produce electrical energy having
ultrasonic frequency.
The ultrasonic motor 35 may be one of a variety of
electromechanical types, such as electrodynamic, piezoelectric or
magnetostrictive. The ultrasonic motor for effecting surgical
procedures through hand directed tools of suitable configuration,
may be of the type which are readily replaceable or
inter-changeable with other work performing tools in acoustically
vibrated material treating devices, and each work tool member is
rigidly joined, in end-to-end relationship to a connecting body or
acoustic impedance transformer and to a transducer which may form
an insert unit or assembly which is removably supported in a
housing containing a coil in surrounding relationship to the
transducer and receiving alternating current for producing an
alternating electromagnetic field.
The transducer in the ultrasonic motor 35 is longitudinally
dimensioned so as to have lengths which are whole multiples of half
wavelengths of the compressional waves established therein at the
frequency of the biased alternating current supplied so that
longitudinal loops of motion as indicated by arrow 45, occur with
maximum displacement at the distal end 32 of the vibratory element
36 that is rigidly connected to the insert unit. Thus, the optimum
amplitude of longitudinal vibration and hyper-accelerations of
vibratory element 36 is achieved, and such amplitude is determined
by the relationship of the masses on both sides of the nodal region
of the vibratory element which may be made effective to either
magnify or reduce the amplitude of the vibrations received from the
transducer.
The generator 42 is provided with a control means, for setting the
time of duration of the energy by adjusting the dial 47. For power
adjustment dial 49 is provided which controls the amount of power
delivered to the ultrasonic motor. The vibratory stroke of the
output surface 32 of the vibratory element 36 is controlled by
manual setting of the power dial 49 on the generator.
The vibratory probe 30 is provided with guard means 46 that may be
secured to the casing 40 of the motor 35 in any conventional manner
and which may be in the form of a tubular member 51 mounted in
coaxial alignment with the vibratory element 36 and designed to
provide clearance around the vibrating surface in order to prevent
rubbing between the vibratory element and the housing when the tip
is vibrating, thus, preventing generation of heat due to friction.
The protective tubing 51 also serves as an insulator or as a
reflector to prevent ultrasonic energy being radiated except from
the output surface 32. The protective tubing 51 may extend the
length of the vibratory element 36 or beyond it if desired and also
serves to support the front part of the ultrasonic probe 30.
Having thus briefly described one form of instrumentation 30 that
may be utilized to perform operative procedures on the eye, it is
seen that an opening 27 is first required to be formed on the wall
25 of the eye 10, which may be over the pars plana, and that as
illustrated in FIG. 1, supporting means 50 be provided to extend
through the opening 27 to lend support to the instrumentation 30
extending therethrough. As seen with respect to FIGS. 2-5, the
opening 27 extends through the sclera 22 and ciliary body 24 over
the most convenient region of the pars plana.
The supporting means 50, which may be of a metallic or
thermoplastic material, as seen with respect to FIGS. 2-5, extends
through the wall 25 and is positioned in and tightened in the
incision or opening 27 by a double mattress suture 52. The support
means 50 should have the ability to rotate within the opening 27.
To provide a seal with the protective tubing 51 and facilitate its
sliding, the supporting member 50 should have a minimum outside
diameter to be inserted into the incision 27, and possibly
supported and rotated by a micromanipulator. Finally the supporting
member 50 should eventually provide for an increase in volume of
the vitreous cavity in order to reduce the pressure in the eye 10,
during the operation. The supporting means 50 comprises a tubular
body portion 53 which may be of circular cross-sectional area so
that it may be rotatable after it is seated through the wall 25 of
the eye 10 and includes a passageway 54 connecting the interior of
the eye to the exterior, and extending from the front end 56 to the
rear end 58, which rear end has an upper annular flange 60
extending radially outwardly from the body portion 53 proximate the
upper end thereof and adapted to overlap the outer surface of the
eye 10. A lower annular flange 62 is provided extending radially
outwardly from the body portion 53 proximate the lower end thereof
and adapted to extend over the inner surface of the wall portion
25. The spacing between the flanges forming retaining means 63 in
the form of a groove 64, which as illustrated is adapted to retain
the wall portion 25 of the eye 10 in fixed position.
The passageway 54 should be of sufficient volume for retreat of the
vitreous material from the tense eye without the possibility of it
running out and being lost. Sealing means 65 is provided in the
passageway 54 to prevent any of the internal fluids of the eye from
flowing out when the instrument 30 extends through the passageway
54. The sealing means 65 may include a seat or groove 66 containing
a sealing member 68, which may be in the form of an o-ring to
provide the sealing engagement with any element inserted within the
passageway 54. Due to the viscosity of the vitreous material a
close tolerance at one point in THE passageway 54 with the
protective tubing 51, or other instrument, may be sufficient to
provide the sealing engagement.
The supporting means 50 has mounted coaxially therewith cutting
means in the form of cutting element 70 which includes an enlarged
head section 72, adapted to be coupled to an instrument if desired,
and having a base section 74 extending through the passageway 54
and terminating in a cutting surface 76 of a selected
configuration. Locking means 78 is provided between the supporting
means 50 and cutting means 70 to releasably connect them together
and permit the removal of the cutting means 70 after the supporting
means 50 has penetrated the wall 25 and is held in place by the
retaining means 63. The locking means 78 may be in the form of a
pin 80 extending from the base section 74 into a cooperating groove
82 contained within the passageway 54 to prevent angular rotation
between said respective means during their insertion into the eye
in the direction of arrow 84.
The cutting means 70, which may be of a metallic material, is
illustrated in greater detail in FIGS. 6-14, and is seen to include
the head section 72 that may be integrally formed with the base
section 74 terminating in a cutting surface 76 including spaced
apart cutting edges 77, approximately 180.degree. apart, that are
joined at one end at the pointed tip 79 and progressively taper
outwardly therefrom until merging in the base section 74 having a
circular cross-section as seen in FIG. 14. The forward end of the
base section 74 terminates in a conically tapered section 81 that
blends with the cutting edges 77. Although two cutting edges 77
have been shown on a common plane, one, or more than two, cutting
edges may also be used, and spaced apart in any selective pattern.
The cutting edges 77 are contained on the base section 74 beyond
the supporting means 50 such that the cutting surface 76 will first
penetrate the wall 25 to form the opening 27 for receiving the
supporting means 50 in seated position within the opening.
In actual practice the combined supporting means 50 and cutting
means 70 are releasably coupled together as a unit and inserted in
the direction of arrow 84 as seen in FIG. 2, such that the cutting
surface 76 first pierces the wall 25 and is moved axially forward
until the position in FIG. 3 is reached with the supporting means
50 positioned in the opening 27 that is formed by the cutting
surface 76. The contour of the cutting surface 76 being pressed
into the eye 10 is of increasing cross-section and designed as a
conical shape until it embraces the groove 64 of the supporting
means 50. The lower flange 62 has a rounded edge 86 and tapered
front such as to continue essentially the taper of the cutting
surface 76, as it is forced through the wall 25. Once the position
in FIG. 3, is reached the wall 25 extends within the groove 64
thereby retaining the supporting means 50 in fixed position against
axial movement and the two mattress sutures 52 may be conveniently
tightened in surrounding relation so as to prevent any of the
vitreous material from flowing out and providing sealing engagement
between the supporting means 50 and wall 25.
The cutting element 70 can now be withdrawn, by disengaging or
unlocking the locking means 78 and removing the cutting element 70
in the direction of arrow 85, leaving the passageway 54 open and in
which case part of the vitreous material will tend to flow therein.
It is now possible to insert through the passageway 54 different
tools and instruments 30 which normally could be attached to a
solid structure like a micromanipulator, which will provide the
stability and a supporting point for the front of the instrument,
thus relieving the strain on the surgeon's hand.
Removal of the supporting sleeve, when required, is accomplished,
as seen in FIG. 5, by inserting removing means 87 which may include
an enlarged rear section 88 that may be gripped by a surgical
device, and a front section 89 adapted to extend within the
passageway 54 with a tapered front end, to minimize damage on the
eye tissue during the withdrawal of the supporting means 50 by
providing a smooth and gentle removal. During this latter process,
an additional or the same pair of mattress sutures 52 are to be
gradually tightened as the supporting means 50 and removing means
87 are gradually removed from the wall 25 to close up the opening
27. The locking means 78 is used to retain the removing means 87
and supporting means 50 coupled together during their removal from
the wall.
As discussed above the puncturing or cutting element 70 is a
pointed two edged knife, designed to start an incision and enlarge
it to the proper length in the desired direction, the direction is
defined by the positioning pin 80 contained thereon. An advantage
of reinserting of a conically pointed rod into the passageway 54
before the removal of the supporting member 50 is that it forces
the vitreous material from the passageway 54 back within to the
eye. Insertion of the rod into the eye increases the pressure in
the eye, thus reducing the clamping force around the supporting
member, facilitating its removal.
Accordingly, once the supporting member 50 is in place, as seen in
FIG. 4, guard means 46 is in sealing engagement with the o-ring 68
and the vibratory element 36 extends therethrough and as seen by
the arrow 48 the support member may be angularly tilted such that
the distal end thereof may be properly manipulated to the desired
position for propagating the energy waves.
Many other changes could be effected in the particular
constructions, and in the methods of use and construction, and in
specific details thereof, hereinbefore set forth, without
substantially departing from the invention intended to be defined
herein, the specific description being merely of embodiments
capable of illustrating certain principles of the invention.
* * * * *